rpm activated vtec bad?
02-25-2008, 10:12 AM
#1
Junior Member
Thread Starter
Join Date: Oct 2007
Location: Rapid City, SD and Chaska, MN
Posts: 327
Likes: 0
Received 0 Likes
on
0 Posts
rpm activated vtec bad?
Hey guys I'm doing a y8 head swap on my D16y7 and I was wondering if using an rpm activated switch would be bad for the car. As far as I know when vtec is activated by a vtec ECU the computer switches over to the high-cam profile timing/fuel maps. Some people use an rpm activated switch to turn the vtec solinoid on/off, could this possibly damage the motor somehow?
I would think a setup with a vtec ecu would have more performance than just an rpm switch because the vtec ecu can switch to high cam maps and adjust timing and fuel according.
Versus the switch which will activate vtec and the non-vtec ecu will just see increased airflow and add more fuel and not switch to a different map so ignition timing would stay the same.
Am I right in this thinking?
I would think a setup with a vtec ecu would have more performance than just an rpm switch because the vtec ecu can switch to high cam maps and adjust timing and fuel according.
Versus the switch which will activate vtec and the non-vtec ecu will just see increased airflow and add more fuel and not switch to a different map so ignition timing would stay the same.
Am I right in this thinking?
02-25-2008, 10:26 AM
#2
Honda-Tech Member
Join Date: Oct 2002
Location: chicago burbs, Il, USA
Posts: 5,150
Likes: 0
Received 23 Likes
on
23 Posts
low cam maps and high cam maps are totally different.
tossing in a RPM switch for VTEC control may work to turn on the solenoid, but the car will run lean and have the wrong ignition mapping.
(NOTE: WOT the ECU does not use the O2 to determine how much fuel to push in, which means lean conditions at the worst possible time, which means melting parts)
tossing in a RPM switch for VTEC control may work to turn on the solenoid, but the car will run lean and have the wrong ignition mapping.
(NOTE: WOT the ECU does not use the O2 to determine how much fuel to push in, which means lean conditions at the worst possible time, which means melting parts)
02-25-2008, 10:30 AM
#3
Darth ModerVader
Re: rpm activated vtec bad? (civicjoe)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civicjoe »</TD></TR><TR><TD CLASS="quote"> I would think a setup with a vtec ecu would have more performance than just an rpm switch because the vtec ecu can switch to high cam maps and adjust timing and fuel according.</TD></TR></TABLE>
Yes, you are completely correct.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civicjoe »</TD></TR><TR><TD CLASS="quote">Versus the switch which will activate vtec and the non-vtec ecu will just see increased airflow and add more fuel and not switch to a different map so ignition timing would stay the same.</TD></TR></TABLE>
Actually, under WOT conditions, the ECU won't compensate for any additional airflow because it will be utilising the open-loop stored maps, which are not optimised for VTEC operation. Under partial-throttle conditions, the O2 sensor will be used to adjust the A/F mixture.
Yes, you are completely correct.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civicjoe »</TD></TR><TR><TD CLASS="quote">Versus the switch which will activate vtec and the non-vtec ecu will just see increased airflow and add more fuel and not switch to a different map so ignition timing would stay the same.</TD></TR></TABLE>
Actually, under WOT conditions, the ECU won't compensate for any additional airflow because it will be utilising the open-loop stored maps, which are not optimised for VTEC operation. Under partial-throttle conditions, the O2 sensor will be used to adjust the A/F mixture.
02-25-2008, 10:31 AM
#4
Cool Cool Island Breezes. BOY-EE
iTrader: (1)
Join Date: Sep 2006
Location: TRILLINOIS....WAY downtown, jerky.
Posts: 11,953
Likes: 0
Received 4 Likes
on
4 Posts
Re: (Relic1)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Relic1 »</TD></TR><TR><TD CLASS="quote">low cam maps and high cam maps are totally different.
tossing in a RPM switch for VTEC control may work to turn on the solenoid, but the car will run lean and have the wrong ignition mapping.
(NOTE: WOT the ECU does not use the O2 to determine how much fuel to push in, which means lean conditions at the worst possible time, which means melting parts)</TD></TR></TABLE>
True, but it's just a D series. It wont melt parts. It just wont make power. I mean...it wont make power NA ever...but it will make even less power if you run it on the wrong map.
Basically, for example, since the HP change is 20hp from a Y7 to a Y8, you may only experience about 5hp or less of a gain with the RPM switch method since the fuel ratios and ignition timing is still for non vtec operation.
Go buy a manual Y8 ECU. Hopefully you have a manual Y8 manifold or a 92-95 D series manifold. Without that, you wont have the right ECU/IACV combo. (I'm assuming your car is manual.)
tossing in a RPM switch for VTEC control may work to turn on the solenoid, but the car will run lean and have the wrong ignition mapping.
(NOTE: WOT the ECU does not use the O2 to determine how much fuel to push in, which means lean conditions at the worst possible time, which means melting parts)</TD></TR></TABLE>
True, but it's just a D series. It wont melt parts. It just wont make power. I mean...it wont make power NA ever...but it will make even less power if you run it on the wrong map.
Basically, for example, since the HP change is 20hp from a Y7 to a Y8, you may only experience about 5hp or less of a gain with the RPM switch method since the fuel ratios and ignition timing is still for non vtec operation.
Go buy a manual Y8 ECU. Hopefully you have a manual Y8 manifold or a 92-95 D series manifold. Without that, you wont have the right ECU/IACV combo. (I'm assuming your car is manual.)
02-25-2008, 10:43 AM
#5
Honda-Tech Member
Re:
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B serious »</TD></TR><TR><TD CLASS="quote">Go buy a manual Y8 ECU. Hopefully you have a manual Y8 manifold or a 92-95 D series manifold. Without that, you wont have the right ECU/IACV combo. (I'm assuming your car is manual.)</TD></TR></TABLE>
I agree. Getting a new ECU will solve all your worries and you won't have to worry about jerry-rigging something up.
[insert mindless plug here]
If you do go the route of the manual trans Y8 ECU, I have one for sale. Check my sig, it's the P2P listed. I can let it go pretty cheap. PM me if interested.
I agree. Getting a new ECU will solve all your worries and you won't have to worry about jerry-rigging something up.
[insert mindless plug here]
If you do go the route of the manual trans Y8 ECU, I have one for sale. Check my sig, it's the P2P listed. I can let it go pretty cheap. PM me if interested.
02-25-2008, 10:50 AM
#7
Honda-Tech Member
Join Date: Jan 2006
Location: Rochester, New York -> Santa Clara, CA
Posts: 10,443
Likes: 0
Received 2 Likes
on
2 Posts
Re: rpm activated vtec bad? (Padawan)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Padawan »</TD></TR><TR><TD CLASS="quote">
Yes, you are completely correct.
Actually, under WOT conditions, the ECU won't compensate for any additional airflow because it will be utilising the open-loop stored maps, which are not optimised for VTEC operation. Under partial-throttle conditions, the O2 sensor will be used to adjust the A/F mixture. </TD></TR></TABLE>
I could be completely wrong on this but I thought under partial throttle the ECU also read sensor readings from the MAP and/or IAT sensor(s) in unison with the reading from the O2 sensor to decide the optimal engagement point adjustment.
Yes, you are completely correct.
Actually, under WOT conditions, the ECU won't compensate for any additional airflow because it will be utilising the open-loop stored maps, which are not optimised for VTEC operation. Under partial-throttle conditions, the O2 sensor will be used to adjust the A/F mixture. </TD></TR></TABLE>
I could be completely wrong on this but I thought under partial throttle the ECU also read sensor readings from the MAP and/or IAT sensor(s) in unison with the reading from the O2 sensor to decide the optimal engagement point adjustment.
Trending Topics
02-25-2008, 10:53 AM
#8
Cool Cool Island Breezes. BOY-EE
iTrader: (1)
Join Date: Sep 2006
Location: TRILLINOIS....WAY downtown, jerky.
Posts: 11,953
Likes: 0
Received 4 Likes
on
4 Posts
Re: rpm activated vtec bad? (Syndacate)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Syndacate »</TD></TR><TR><TD CLASS="quote">
I could be completely wrong on this but I thought under partial throttle the ECU also read sensor readings from the MAP and/or IAT sensor(s) in unison with the reading from the O2 sensor to decide the optimal engagement point adjustment.</TD></TR></TABLE>
The engagement point doesn't really change. The RPM trigger is the same. It has to be at that trigger or greater.
For example, you could roll into the 4500rpm trigger with less than required throttle position. At that point, (at the risk of sounding cliche), the VTEC system would be "armed and ready". When the rest of the parameters are met, VTEC will actually operate.
However, if you sit at very low throttle position, but manage to rev the car to redline, VTEC will never operate.
All the parameters have to be met, but the trigger point never changes.
I could be completely wrong on this but I thought under partial throttle the ECU also read sensor readings from the MAP and/or IAT sensor(s) in unison with the reading from the O2 sensor to decide the optimal engagement point adjustment.</TD></TR></TABLE>
The engagement point doesn't really change. The RPM trigger is the same. It has to be at that trigger or greater.
For example, you could roll into the 4500rpm trigger with less than required throttle position. At that point, (at the risk of sounding cliche), the VTEC system would be "armed and ready". When the rest of the parameters are met, VTEC will actually operate.
However, if you sit at very low throttle position, but manage to rev the car to redline, VTEC will never operate.
All the parameters have to be met, but the trigger point never changes.
02-25-2008, 10:55 AM
#9
Honda-Tech Member
Join Date: Jan 2006
Location: Rochester, New York -> Santa Clara, CA
Posts: 10,443
Likes: 0
Received 2 Likes
on
2 Posts
Re: rpm activated vtec bad? (B serious)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B serious »</TD></TR><TR><TD CLASS="quote">
The engagement point doesn't really change. The RPM trigger is the same. It has to be at that trigger or greater.
For example, you could roll into the 4500rpm trigger with less than required throttle position. At that point, (at the risk of sounding cliche), the VTEC system would be "armed and ready". When the rest of the parameters are met, VTEC will actually operate.
However, if you sit at very low throttle position, but manage to rev the car to redline, VTEC will never operate.
All the parameters have to be met, but the trigger point never changes.</TD></TR></TABLE>
I know, but the parameter requirements are only temperature, not in neutral, RPM, and a few other things. I'm pretty sure VTEC will still engage if you use a low throttle position to put your car to the redline, but it will engage later than the standard 4800 RPM that it would at WOT.
The engagement point doesn't really change. The RPM trigger is the same. It has to be at that trigger or greater.
For example, you could roll into the 4500rpm trigger with less than required throttle position. At that point, (at the risk of sounding cliche), the VTEC system would be "armed and ready". When the rest of the parameters are met, VTEC will actually operate.
However, if you sit at very low throttle position, but manage to rev the car to redline, VTEC will never operate.
All the parameters have to be met, but the trigger point never changes.</TD></TR></TABLE>
I know, but the parameter requirements are only temperature, not in neutral, RPM, and a few other things. I'm pretty sure VTEC will still engage if you use a low throttle position to put your car to the redline, but it will engage later than the standard 4800 RPM that it would at WOT.
02-25-2008, 11:41 AM
#10
Cool Cool Island Breezes. BOY-EE
iTrader: (1)
Join Date: Sep 2006
Location: TRILLINOIS....WAY downtown, jerky.
Posts: 11,953
Likes: 0
Received 4 Likes
on
4 Posts
Re: rpm activated vtec bad? (Syndacate)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Syndacate »</TD></TR><TR><TD CLASS="quote">
I know, but the parameter requirements are only temperature, not in neutral, RPM, and a few other things. I'm pretty sure VTEC will still engage if you use a low throttle position to put your car to the redline, but it will engage later than the standard 4800 RPM that it would at WOT. </TD></TR></TABLE>
Nope. You can roll into VTEC range and duck below the TPS limit. VTEC will not operate. IIRC, it's like 25% throttle or something.
Lets say that it's 25% throttle. If you get into VTEC RPM (let's say 4800) at like 26% throttle, it will operate at 4800. However, if you go to 7500 at 24% throttle, VTEC will never operate. It looks for all parameters at a certain RPM. If they are met by any RPM after trigger point, it will activate VTEC. If all of them are never met, VTEC will never activate.
Parameters:
Coolant at operating temp
TPS at or above certain position
VTEC hardware/software/wiring in good working order
oil press
RPM signal exists and is at or above trigger
Speed signal exists and is at or above around 15mph
I know, but the parameter requirements are only temperature, not in neutral, RPM, and a few other things. I'm pretty sure VTEC will still engage if you use a low throttle position to put your car to the redline, but it will engage later than the standard 4800 RPM that it would at WOT. </TD></TR></TABLE>
Nope. You can roll into VTEC range and duck below the TPS limit. VTEC will not operate. IIRC, it's like 25% throttle or something.
Lets say that it's 25% throttle. If you get into VTEC RPM (let's say 4800) at like 26% throttle, it will operate at 4800. However, if you go to 7500 at 24% throttle, VTEC will never operate. It looks for all parameters at a certain RPM. If they are met by any RPM after trigger point, it will activate VTEC. If all of them are never met, VTEC will never activate.
Parameters:
Coolant at operating temp
TPS at or above certain position
VTEC hardware/software/wiring in good working order
oil press
RPM signal exists and is at or above trigger
Speed signal exists and is at or above around 15mph
02-25-2008, 12:06 PM
#11
Honda-Tech Member
Join Date: Oct 2002
Location: chicago burbs, Il, USA
Posts: 5,150
Likes: 0
Received 23 Likes
on
23 Posts
Re: rpm activated vtec bad? (B serious)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B serious »</TD></TR><TR><TD CLASS="quote">Parameters:
Coolant at operating temp
TPS at or above certain position
VTEC hardware/software/wiring in good working order
oil press
RPM signal exists and is at or above trigger
Speed signal exists and is at or above around 15mph</TD></TR></TABLE>
and the CEL is not on.
(some OBD2 CELs will not prevent VTEC, but most will)
Coolant at operating temp
TPS at or above certain position
VTEC hardware/software/wiring in good working order
oil press
RPM signal exists and is at or above trigger
Speed signal exists and is at or above around 15mph</TD></TR></TABLE>
and the CEL is not on.
(some OBD2 CELs will not prevent VTEC, but most will)
02-25-2008, 12:12 PM
#12
Cool Cool Island Breezes. BOY-EE
iTrader: (1)
Join Date: Sep 2006
Location: TRILLINOIS....WAY downtown, jerky.
Posts: 11,953
Likes: 0
Received 4 Likes
on
4 Posts
Re: rpm activated vtec bad? (Relic1)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Relic1 »</TD></TR><TR><TD CLASS="quote">
and the CEL is not on.
(some OBD2 CELs will not prevent VTEC, but most will)</TD></TR></TABLE>
It depends on what the CEL is for. My B16A still has VTEC with a CEL on for a primary O2 sensor.
My friend's 97 EX's VTEC works with several CELs.
Honda is surprisingly liberal about their "limp mode" operation. If the CEL is for a major fuel sensor, that may fall under the "VTEC software/programming" category.
For example: MAP sensor codes, IAT codes, TPS codes.
and the CEL is not on.
(some OBD2 CELs will not prevent VTEC, but most will)</TD></TR></TABLE>
It depends on what the CEL is for. My B16A still has VTEC with a CEL on for a primary O2 sensor.
My friend's 97 EX's VTEC works with several CELs.
Honda is surprisingly liberal about their "limp mode" operation. If the CEL is for a major fuel sensor, that may fall under the "VTEC software/programming" category.
For example: MAP sensor codes, IAT codes, TPS codes.
02-25-2008, 12:25 PM
#13
Junior Member
Thread Starter
Join Date: Oct 2007
Location: Rapid City, SD and Chaska, MN
Posts: 327
Likes: 0
Received 0 Likes
on
0 Posts
Re: rpm activated vtec bad?
I'm surprised at the attention this thread has gotten already thanks everyone! Just reading the tutorials I noticed some people used rpm switches in their vtec head swap and was wondering if that was effective. I guess it isn't.
I'm going to switch over to OBD1 and go with a P28 ECU. Turbo is in the works and I'm gonna shoot for a moderate goal of 180 whp on stock internals. I'm planning on learning to tune so I'm gonna start out with D-series cause they're a lot cheaper to blow up than B series.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B serious »</TD></TR><TR><TD CLASS="quote">
True, but it's just a D series. It wont melt parts. It just wont make power. I mean...it wont make power NA ever...but it will make even less power if you run it on the wrong map.
Basically, for example, since the HP change is 20hp from a Y7 to a Y8, you may only experience about 5hp or less of a gain with the RPM switch method since the fuel ratios and ignition timing is still for non vtec operation.
Go buy a manual Y8 ECU. Hopefully you have a manual Y8 manifold or a 92-95 D series manifold. Without that, you wont have the right ECU/IACV combo. (I'm assuming your car is manual.)
</TD></TR></TABLE>
Since I'm going with the P28 ECU I won't need the y8 manifold right?
I was thinking that the y7 manifold and IACV would work if I use a P28 ECU.
I'm going to switch over to OBD1 and go with a P28 ECU. Turbo is in the works and I'm gonna shoot for a moderate goal of 180 whp on stock internals. I'm planning on learning to tune so I'm gonna start out with D-series cause they're a lot cheaper to blow up than B series.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B serious »</TD></TR><TR><TD CLASS="quote">
True, but it's just a D series. It wont melt parts. It just wont make power. I mean...it wont make power NA ever...but it will make even less power if you run it on the wrong map.
Basically, for example, since the HP change is 20hp from a Y7 to a Y8, you may only experience about 5hp or less of a gain with the RPM switch method since the fuel ratios and ignition timing is still for non vtec operation.
Go buy a manual Y8 ECU. Hopefully you have a manual Y8 manifold or a 92-95 D series manifold. Without that, you wont have the right ECU/IACV combo. (I'm assuming your car is manual.)
</TD></TR></TABLE>
Since I'm going with the P28 ECU I won't need the y8 manifold right?
I was thinking that the y7 manifold and IACV would work if I use a P28 ECU.
02-25-2008, 12:28 PM
#14
Cool Cool Island Breezes. BOY-EE
iTrader: (1)
Join Date: Sep 2006
Location: TRILLINOIS....WAY downtown, jerky.
Posts: 11,953
Likes: 0
Received 4 Likes
on
4 Posts
Re: rpm activated vtec bad? (civicjoe)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civicjoe »</TD></TR><TR><TD CLASS="quote">
I'm going to switch over to OBD1 and go with a P28 ECU. Turbo is in the works and I'm gonna shoot for a moderate goal of 180 whp on stock internals. I'm planning on learning to tune so I'm gonna start out with D-series cause they're a lot cheaper than B series.
Since I'm going with the P28 ECU I won't need the y8 manifold right?
I was thinking that the y7 manifold and IACV would work.
</TD></TR></TABLE>
The Y7 manifold and IACV will DEFINATELY not work with a P28. It will only work with an automatic P2P.
You need a 92-95 D manifold or 96+ Y8 manual manifold.
I'm going to switch over to OBD1 and go with a P28 ECU. Turbo is in the works and I'm gonna shoot for a moderate goal of 180 whp on stock internals. I'm planning on learning to tune so I'm gonna start out with D-series cause they're a lot cheaper than B series.
Since I'm going with the P28 ECU I won't need the y8 manifold right?
I was thinking that the y7 manifold and IACV would work.
</TD></TR></TABLE>
The Y7 manifold and IACV will DEFINATELY not work with a P28. It will only work with an automatic P2P.
You need a 92-95 D manifold or 96+ Y8 manual manifold.
02-25-2008, 12:48 PM
#15
Junior Member
Thread Starter
Join Date: Oct 2007
Location: Rapid City, SD and Chaska, MN
Posts: 327
Likes: 0
Received 0 Likes
on
0 Posts
Re: rpm activated vtec bad? (B serious)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B serious »</TD></TR><TR><TD CLASS="quote">
The Y7 manifold and IACV will DEFINATELY not work with a P28. It will only work with an automatic P2P.
You need a 92-95 D manifold or 96+ Y8 manual manifold.</TD></TR></TABLE>
Alrighty, I should be able to find those. Do I need just the manifold or do I need the throttle body too? From what I've heard it's the ecu/IACV combo that has to work and on all my old cars the IACV was on the throttle body.
Just to be clear what is the difference between the y7 and y8 manifolds? I'd think they'd have the same MAP sensor, where's the difference?
oh and yes it's a manual of course. After I'm done with this I'm swapping out the tranny for one from an EX. I currently have a CX and AFAIK it has the highest gearing of the EK generation.
B serious, you know your stuff. Thought I'd ask you about something else. I saw somewhere that the P28 looks for a four wire O2 sensor, is that right?
Also, the P28 doesn't look for the second O2 or the knock sensor right?
Anything else I need to know?
Sorry if I'm asking a lot of questions, I've read all the how-to's and am quite acquainted with the search function
The Y7 manifold and IACV will DEFINATELY not work with a P28. It will only work with an automatic P2P.
You need a 92-95 D manifold or 96+ Y8 manual manifold.</TD></TR></TABLE>
Alrighty, I should be able to find those. Do I need just the manifold or do I need the throttle body too? From what I've heard it's the ecu/IACV combo that has to work and on all my old cars the IACV was on the throttle body.
Just to be clear what is the difference between the y7 and y8 manifolds? I'd think they'd have the same MAP sensor, where's the difference?
oh and yes it's a manual of course. After I'm done with this I'm swapping out the tranny for one from an EX. I currently have a CX and AFAIK it has the highest gearing of the EK generation.
B serious, you know your stuff. Thought I'd ask you about something else. I saw somewhere that the P28 looks for a four wire O2 sensor, is that right?
Also, the P28 doesn't look for the second O2 or the knock sensor right?
Anything else I need to know?
Sorry if I'm asking a lot of questions, I've read all the how-to's and am quite acquainted with the search function
02-25-2008, 01:29 PM
#16
Honda-Tech Member
Join Date: Oct 2002
Location: chicago burbs, Il, USA
Posts: 5,150
Likes: 0
Received 23 Likes
on
23 Posts
Re: rpm activated vtec bad? (civicjoe)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civicjoe »</TD></TR><TR><TD CLASS="quote">oh and yes it's a manual of course. After I'm done with this I'm swapping out the tranny for one from an EX. I currently have a CX and AFAIK it has the highest gearing of the EK generation.</TD></TR></TABLE>
trans specs... http://hondaswap.com/reference...29132/
depends on if it's a hatch or coupe/sedan
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote »</TD></TR><TR><TD CLASS="quote">I saw somewhere that the P28 looks for a four wire O2 sensor, is that right?</TD></TR></TABLE>
correct
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote »</TD></TR><TR><TD CLASS="quote">Also, the P28 doesn't look for the second O2 or the knock sensor right?</TD></TR></TABLE>
correct, OBD1 does not use the secondary O2. The P30 and P72 are the two main OBD1 ECUs that have the knock sensor ability.
trans specs... http://hondaswap.com/reference...29132/
depends on if it's a hatch or coupe/sedan
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote »</TD></TR><TR><TD CLASS="quote">I saw somewhere that the P28 looks for a four wire O2 sensor, is that right?</TD></TR></TABLE>
correct
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote »</TD></TR><TR><TD CLASS="quote">Also, the P28 doesn't look for the second O2 or the knock sensor right?</TD></TR></TABLE>
correct, OBD1 does not use the secondary O2. The P30 and P72 are the two main OBD1 ECUs that have the knock sensor ability.
Thread
Thread Starter
Forum
Replies
Last Post
philkehn
Honda CRX / EF Civic (1988 - 1991)
10
10-03-2006 11:55 AM
blkhatch92
Honda CRX / EF Civic (1988 - 1991)
5
11-29-2005 11:04 AM
