I just finished my mini-me:
1997 DX (D16Y7) engine block with everything else off of a 1996 EX (D16Y8)
A few seconds after starting the car, the engine began stalling

I checked the code and this is what I got:
P0450 (Emission Control System Press Sensor Fault)

What should I do?

 

Please help. I need the car running so I could go to school and work.

More info.
The car stalls after 15 seconds of running and does not restart until the codes are deleted.
After the code is deleted and the car is restarted, the code appears within 15 seconds and the engine shuts off again.

 

Comon, help me out

 

Well did you hook the EVAP system back up?? there should be one two wire sensor, and vaccum lines. One leading to the intake manifold/throttle body, one to the sensor and one to the canister itself. Thats it.

 

I think I did. It’s the sensor on the Y8 fuel rail, right? And has two hoses, one going form intake manifold to sensor, and another, from sensor to the can.


This is what’s happening
-Check engine light, code P0450 (Emission Control System Press Sensor Fault)
-Engine dies within 15 seconds of being started.
-Unless the code is erased, the engine does not restart.
-RPM idles below 500.
-If I depress the gas pedal to hold the rpm at 1000, it keeps erratically jumping from 500 to 1500 and back.
-Engine revs up very sluggishly, bare goes over 2500rpm.

 

What ecu are you using? And if your using the ex one then did you do the 3 wire to 2 wire iacv conversion? The reason I ask is because well, I forgot what the 2 wire plug to the iacv looked like on the obd2 motors but is it possible that you plugged the iavc plug into the purge control solenoid and the purge control solenoid plug into the iacv. I did a mini-me 4 years ago and everything ran perfect. I don't know what else to check. i can't think of anything else. Its kinda hard by not seeing what you did and how you did it.

And i'm looking in my helms book for 96-00 civics and I don't see the P0450 code!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hondadriver &raquo;</TD></TR><TR><TD CLASS="quote">What ecu are you using? And if your using the ex one then did you do the 3 wire to 2 wire iacv conversion?
And i'm looking in my helms book for 96-00 civics and I don't see the P0450 code!</TD></TR></TABLE>

I'm using a p2p, and since my car is an automatic, I don't have to do the three wire conversion.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hondadriver &raquo;</TD></TR><TR><TD CLASS="quote">
And i'm looking in my helms book for 96-00 civics and I don't see the P0450 code!</TD></TR></TABLE>
That's the code my OBD2 plug in code reader gave me.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hondadriver &raquo;</TD></TR><TR><TD CLASS="quote">
The reason I ask is because well, I forgot what the 2 wire plug to the iacv looked like on the obd2 motors but is it possible that you plugged the iavc plug into the purge control solenoid and the purge control solenoid plug into the iacv.</TD></TR></TABLE>

I don't think it's the same plug, but I'll check

 

any ideas?

 

I get a total of 3 codes:
P0325 - knock sensor 1 circuit malfunction bank 1 or 1 sensor
P0453 - EVAP emission control system press sensor high
P0450 - EVAP emission control system press sensor fault

The knock sensor is showing because I haven't installed it yet, but what can I do about the other two.

Are Vtec (5spd) and Vtec (auto) EVAP sensors the same? What about non-vtec (auto)?

The EVAP sensor I'm using is off of a 5spd Vtec, hooked up to non-vtec auto harness, and plugged into Vtec (p2p) auto ecu.

 

HELP!

 

The p0453 is the Fuel Tank Pressure sensor. And in the helms book it says it could be

- Open in the fuel tank pressure tank circuit
- Fuel tank pressure sensor
- Ecm/pcm


When I did my swap i just kept my y7 IM, and I just used a rpm switch for the vtec, which elimated any stupid codes along with the vtec press, and knock. I had my setup for 2.5 years, and it ran fine with the rpm switch. If I were you I would just use the stock ecu with a rpm activated switch. Its just simple that way, and you won't have any of these codes. And like you said since your car is auto it already had the 3 wire iacv. Alot of people say that the rpm activated switches burn out the vtec solenoid, but it won't becasue it doesn't matter if the ecu is throwing out 12v+ or if the rpm activated switch is throwing out 12v+. Just make sure you set it to the right rpm, and only go into vtec when your car is warmed up and you know you have enough oil presure.

Its kinda hard to trouble shoot a code when your useing a different ecu in a car it wasn't made for, becasue maybe the ex ecu is looking for a evap or fuel tank pressure sensor that you car doesn't have. A motor is a motor, theres no difference there besides vtec but once you get into the evap system every model differs in the evap system.


******And i just found one problem your having in the helms book. I have pictures of the evap system on the 97 dx and the 96-00 lx and ex models. The 97 dx doesn't have a evap control canister shut off valve on the charcoal canister, but the 96-00 lx and ex do. So that could be causing you to throw the P0450.

 

Thanks, I'll try running my p2e ECU and see how it goes.
If the codes/problems disappear, I'll probably have to do what you did and go with the RPM switch.

Would it be hard to wire in the EVAP shut off valve?

 

check the gas cap to see if it loose.

 

The gas cap is fine, but I’m not too sure about the gas itself.
Although my gas tank was empty, I’m sure there was some gas left in the fuel lines, and my car was sitting in the garage for a few months now with no fuel stabilizer.
Although it was probably just a few ounces of gas, could this be causing the problem now. It would kind of explain why the exhaust was spiting out water the first time I started it.

My gas tank is currently filled up with 9-10 gallons of 92 octane + “104 Octane booster,” so the few ounces of degraded gas shouldn’t really affect it, right? Plus it would have burned off the first 10-15 I ran my engine.

 

Why are you running the 92 + 104 boost. There is no need for that. the regular 87 or 89 is good enough, your not changing your compression by much, almost nothing at all. nothing is gonna happen to your gas after sitting in the garage for a while, My car sits in the garage for 6+ months on the winter and when spring comes it starts right up. And the water is just moisture in you motor, exhaust, and it could be the by-product of your combustion.

An no the canister shut of valve is not hard to wire up. You'll just need the charcoal canister off an ex, and they come with the shut off vavle already on it. I bought a while ago trying to figure out my p1457 code. And I paid I think like over $100+ brand new for it. Unless you can get a used one. And then you'll you just have to run two wires to it, one wire goes to the ecu and the other goes to the blk/yel junction clip under your IM. The junction clips are the 2 plugs that look like they are not connected to nothing under you IM, one is blu and the other is gray(I think).

But for the ease of it, I would do a rpm switch so, put your stock ecu back in, you'lll be able to drive your car no problem just like as if you had your stock motor. And then if the codes don't come up then just do the rpm switch. because if use the ex ecu it might cost more to get it to run properly. But this is my opinion and i'm trying to help you out as much as i can.

And the gas cap would be a p1456 code!!!!!

 

Well, I'm running 92octane gas + octane booter because I have a nitrous oxide kit, and it requires a minimum of 92 octane.

It does make sense to change the charcoal canister to the same one as in EX, but in all the mini-me write-ups I read, I don’t think I've head of any one doing this.
But I guess if nothing else helps, I'll have to do this, too.

As for the ECU, I'll try swapping it back tomorrow.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hondadriver &raquo;</TD></TR><TR><TD CLASS="quote">When I did my swap i just kept my y7 IM, and I just used a rpm switch for the vtec, which elimated any stupid codes along with the vtec press, and knock. I had my setup for 2.5 years, and it ran fine with the rpm switch. If I were you I would just use the stock ecu with a rpm activated switch. Its just simple that way, and you won't have any of these codes. And like you said since your car is auto it already had the 3 wire iacv. Alot of people say that the rpm activated switches burn out the vtec solenoid, but it won't becasue it doesn't matter if the ecu is throwing out 12v+ or if the rpm activated switch is throwing out 12v+. Just make sure you set it to the right rpm, and only go into vtec when your car is warmed up and you know you have enough oil presure.

Its kinda hard to trouble shoot a code when your useing a different ecu in a car it wasn't made for, becasue maybe the ex ecu is looking for a evap or fuel tank pressure sensor that you car doesn't have. A motor is a motor, theres no difference there besides vtec but once you get into the evap system every model differs in the evap system.
</TD></TR></TABLE>

This is just freaking stupid. Everyone knows an RPM switch will not get you anywhere close to the power output of the stock ECU for your setup. The timing and fuel curves for VTEC are radically different than the stock curves.

A couple questions...

1. You did swap injectors, correct?
2. The automatic thing is really messing with me. I don't know the diffences between evap stuff on an auto, but everything was identical to the EX on my 97 DX hatch. The code 91 will NOT make your car screw up like that, mine has been on for a month and no problems so far. I'd be most concerned with the knock sensor.

Keep up the good work, it's hard to get these things straight sometimes.

 

At the moment I have a Y7 engine block and everything up (head, IM, injectors, intake, exhaust, wires, sensors, cables ect.) are Y8

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by shifty35 &raquo;</TD></TR><TR><TD CLASS="quote">This is just freaking stupid. Everyone knows an RPM switch will not get you anywhere close to the power output of the stock ECU for your setup. The timing and fuel curves for VTEC are radically different than the stock curves.

A couple questions...

1. You did swap injectors, correct?
2. The automatic thing is really messing with me. I don't know the diffences between evap stuff on an auto, but everything was identical to the EX on my 97 DX hatch. The code 91 will NOT make your car screw up like that, mine has been on for a month and no problems so far. I'd be most concerned with the knock sensor.

Keep up the good work, it's hard to get these things straight sometimes.</TD></TR></TABLE>

Yes the fuel curve and all that is alittle different, but if mine ran fine and I felt vtec then i most have done it right, So its not stupid, its not like i made it up. Before When I first did a search for my mini-me swap, i found alot of people using the rpm switch, thats were I got the idea of using the switch.

1) ex and lx have the same injectors.... So that won't make a difference.
2) If the 97 dx evap system was the same as the ex, then sorry my friend he would not have the evap code. The ex and lx have the same evap system but no the dx, go buy a helms manual for $80 and it has full illustrations of the ex, lx, dx and si evap system And you can see the 97 dx hatch has a diff canister. So your wrong twice, before you call my set up stupid think about what your typing!!!!


Modified by hondadriver at 11:49 PM 4/28/2005

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hondadriver &raquo;</TD></TR><TR><TD CLASS="quote">

Yes the fuel curve and all that is alittle different, but if mine ran fine and I felt vtec then i most have done it right, So its not stupid, its not like i made it up. Before When I first did a search for my mini-me swap, i found alot of people using the rpm switch, thats were I got the idea of using the switch.

1) ex and lx have the same injectors.... So that won't make a difference.
2) If the 97 dx evap system was the same as the ex, then sorry my friend he would not have the evap code. The ex and lx have the same evap system but no the dx, go buy a helms manual for $80 and it has full illustrations of the ex, lx, dx and si evap system And you can see the 97 dx hatch has a diff canister. So your wrong twice, before you call my set up stupid think about what your typing!!!!
</TD></TR></TABLE>

1. Wrong again. EX injectors = 240cc, LX/DX/CX = 180 cc. This is very documented.
2. I did the exact same swap on the SAME YEAR DX (97) a week ago, and I have to evap codes. Explain that one.

I'm not calling your setup stupid because it won't work, I'm calling it stupid because it is a crappy hack job way of getting it to work.

 

I don’t know if Y7 and Y8 injectors have a different flow, but they do look different
Y7 has green, rounded off tips.
Y8 has brow, a little boxier tips.
Other than that, I don’t for sure what the difference between them is, but I know that my car runs crappy with both sets.

As for the EVAP charcoal canisters, I’ll try taking some pictures this evening.
I have a DX hatchback, and my parents own an LX sedan (both ’97), so I’ll know for sure if DX and LX differ. As for the EX, I’m out of luck, because neither I nor any one I know, owns one.

 

It shouldn't make a difference. I'm using a 97 P2P on a 97 DX with a 98 EX head and I have NO evap codes. I did not swap the charcoal canister. What year ECU are you using?

 

The ECU, head, and all the sensors from engine block up are off of a '96 EX.
My car is a '97 DX