supapoopa

Just put in a dc sports header on a d16y8 and was wondering if anyone else as had or heard of problems when relocating the o2 sensor.

I keep getting the check engine light and the code comes up with an o2 sensor as being the problem. Anyone know what the problem might be? I had to extend the wiring since the original position of the o2 sensor was close to the front of the stock header and the DC sports header has it on the bottom towards the end (close to cat). The wires were soldered together when extending the o2 sensor and everything was taped up and heat shrinked.

Could the o2 sensor be bad? Would relocating the o2 sensor farther down the header prompt the check engine light? Would an exhaust leak between the header and CAT (or rest of piping) trigger the engine light?


Kind of stuck on what to do. Any advice would be great.

Keep in mind that this car has to pass smog testing in California. Would a o2 simulator be able to pass smog testing? Any adverse effects on the car longterm?



Modified by supapoopa at 5:27 PM 11/9/2005

Luserkid

Im thinking you rewired wrong. Did you do it with the batt. on or off? Did you try to reset your codes?

supapoopa

Battery was disconnected. And I've already reset it once. Light comes on a few seconds after startup.


It was only 4 wires and they were all soldered together to the extending wire. I don't see what problem could be with the wiring except that is was extended a good 3-4'. I will probably redo it anyways just be sure that its not the connections.


Any other suggestions?

raminsco

what size wire did you use on the extension?

dogbiscuit

I recently replaced my o2 sensor with a Universal kit o2 sensor, and if i do remember correctly the directions for the wiring did have length specifications, i dunno.

I would say to buy a new sensor but at about $100 it sucks to change if u don't need it. however depending on how old your car is your o2 sensor may just need replacing.

97ShLude

since the header removed the cat, did you put another one back in? Since this is an OBII car there are 2 O2 sensors (you probably already know this), one before the cat and that goes inside of the cat. That second O2 sensor for the cat is probably the one that is throwing the CEL.

There is a cheap way to fix this problem, one that doesn't involve getting an O2 simulator...

Go to the autoparts store and pick up 2 18mm O2 sensor non-foulers. With a 1/2" drill bit, drill the middle out of one of the non-foulers and screw the drilled one into the one that isn't drilled. Take this whole thing and screw it in the bung where you would put the O2 sensor and then screw the O2 sensor in. What the non-foulers do is pull the O2 sensor out of the direct flow of exhaust gas. On the bottom of the non-foulers is a small hole that lets some exhaust in but it is very little, I guess that is what tricks the ecu into thinking the cat is doing its job. I have done this one my S2k when I picked a T1R exhaust and testpipe and I didn't want to mess with an O2 simulator. 10k miles later and still no CEL, so I say it works like a charm and its like a $3 fix.

supapoopa

the code prompted "2nd o2 sensor malfunction" - p01 41b


My friends going to check it this sat to see whats up with the sensors, but if anyone has any ideas what the problem might be with that code ahead of time please let me know. thx.

civic_976

i have the same problems but i for my car i think its the O2 sensor needs to be replace not sure tho, but if you do fix the problem pm'd me cause its annoying driving with the CEL on

urname7698

if you can find someone with a scan tool monitor the O2 voltages.. you may see the problem.. if the code pops up shortly after starting the car it sounds like a wiring issue. Maybe the heater is out or not wired correctly. Also- Go to autozone and get the full code.. the generic flashing one can be a few different codes.. and you can narrow it further:

P0131 Primary Heated Oxygen Sensor (Primary HO2S) (Sensor 1) Circuit Low Voltage
P0132 Primary Heated Oxygen Sensor (Primary HO2S) (Sensor 1) Circuit High Voltage
P0135 Primary Heated Oxygen Sensor (Primary HO2S) (Sensor 1) Heater Circuit Malfunction

P0137 Secondary Heated Oxygen Sensor (Secondary HO2S) Circuit Low Voltage
P0138 Secondary Heated Oxygen Sensor (Secondary HO2S) Circuit High Voltage
P0139 Secondary Heated Oxygen Sensor (Secondary HO2S) Slow Response
P0141 Secondary Heated Oxygen Sensor (Secondary HO2S) (Sensor 2) Heater Circuit Malfunction

For instance I was throwing a code 1, swapped the o2 and it came back (after driving for an hour).. used a scantool and noticed my secondary O2 was staying at 12V.. and I saw this code with the scantool:
P0131 Primary Heated Oxygen Sensor (Primary HO2S) (Sensor 1) Circuit Low Voltage

Turns out it was the ECU comparing the O2s outputs.. so i replaced the secondary and no more CEL.

If you were closer I'd let you use my scantool.. we'd have this fixed in no time..

IHateJDM

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by urname7698 &raquo;</TD></TR><TR><TD CLASS="quote">Turns out it was the ECU comparing the O2s outputs.. </TD></TR></TABLE>

the ecu does compare the readings of both o2 sensors. the secondary reading has to be within a certain range of the 1st. when you extended the wires that far (3-4' is excessive), you changed the signal that the ecu sees. Try shortening the wires you extended as much as possible before you go buy anything.

supapoopa

Had it checked out today and it appears that its actually the o2 sensor in the CAT that is not reading. The voltage didn't move at all when reving the engine ( stuck at 1.25v) so I'm assuming it might of been to ruffed up when changing out the header and exhaust.

Any cheap places to get a o2 sensor for the CAT in a 98 civic ex? Preferably Denso brand. I was quoted $180 for a new sensor at a local shop. It appears to be a different part # then the o2 sensor in the header. thx again for the help.

kkim

when you extended the wires, did you make sure to connect the correct wires to each other? IIRC, there are 4 wires with 2 of them being black. The 2 black wires cannot be "swapped" as they are not both ground as one might think. If you do happen to swap the wires around, the o2 sensor will not work. Did you possibly miswire when you extended them?

I extended my wiring with no problems when I had DC header in my car.

vancoland

http://sparkplugs.com/default.asp

damn...can't believe the secondary o2 sensor is 3 times the cost of the primary

Bond

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kkim &raquo;</TD></TR><TR><TD CLASS="quote">when you extended the wires, did you make sure to connect the correct wires to each other? IIRC, there are 4 wires with 2 of them being black. The 2 black wires cannot be "swapped" as they are not both ground as one might think. If you do happen to swap the wires around, the o2 sensor will not work. Did you possibly miswire when you extended them?

I extended my wiring with no problems when I had DC header in my car.</TD></TR></TABLE>

I would think this is most likely what happened. It's weird cause I got a extended wiring harness for extending the O2 sensor. I just hand to unplug it and plug in the extended wiring harness for the O2 sensor. I wounder why he didn't get the extension piece as it clips right into the stock connectors.

urname7698

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by supapoopa &raquo;</TD></TR><TR><TD CLASS="quote">
Any cheap places to get a o2 sensor for the CAT in a 98 civic ex? Preferably Denso brand. I was quoted $180 for a new sensor at a local shop. It appears to be a different part # then the o2 sensor in the header. thx again for the help.</TD></TR></TABLE>

I ordered mine from Rywire http://rywire.com/store/produc...70932

Go to Honda, swap components, Oxygen sensor. It was about $80 shipped.. great product and its a denso.

supapoopa

Well i bought the header used 'as is' so the money i saved IMO was worth the trouble of rewiring. I figured with the package deal i got with the header, it came out to about $100. The sensors were checked out yesturday with a scanner and it appears that the problem sensor is the secondary o2 sensor, located in the CAT. The rewired o2 sensor appears to be working fine.

Thanks for the links. I think I'll just get it from the shop since I'm only going to be saving $30 through the net (not taking into account the extra shipping) and just incase i get a bad sensor I don't have to deal with reshipping and the waiting game.

Thanks for the help everyone. I'll check back when its hopefully fixed or if there is a new problem.

supapoopa

ONe last question about DC sport header's. Is it required to reuse the stock header gasket (links to CAT), or is it supposed to bolt on with out a gasket?

Sorry of the lame question but i just want to know if DC also supplied a gasket specific to this header or if the factory gasket was to be reused or if the design did not require a gasket.

Thx again for the help.

kkim

I used the stock doughnut silver gasket. I can't see how you can get the header to mate properly to the cat w/o it. I also used all the stock mounting hardware including the spring isolators.

civic_driver

Use gaskets. You don't want exhaust leaks.

Bond

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kkim &raquo;</TD></TR><TR><TD CLASS="quote">I used the stock doughnut silver gasket. I can't see how you can get the header to mate properly to the cat w/o it. I also used all the stock mounting hardware including the spring isolators.</TD></TR></TABLE>

Agreed. I ended up ripping mine and it tore. I then went down to my local auto parts store and $1.50 later I was back in business. Without the gasket, your exhaust would for sure leak.