i recently put a dc 4-2-1 header into my car, and ever since then or close to then my car has been running very rich, there is a tonne of carbon **** on the back of my car. and being white its very easy to see. i have no clue why its doing this.

can anyone help??

-sean

 

did you happen to forget to put back in your O2 sensor? or did it somehow get unplugged during the install? that would be my guess.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by delslo93 &raquo;</TD></TR><TR><TD CLASS="quote">did you happen to forget to put back in your O2 sensor? or did it somehow get unplugged during the install? that would be my guess. </TD></TR></TABLE>

and mine.

 

would there not be a check engine light??

i will go and check but as far as i now it was installed

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GUNNER666 &raquo;</TD></TR><TR><TD CLASS="quote">would there not be a check engine light??

i will go and check but as far as i now it was installed</TD></TR></TABLE>

No there wouldn't be a light becuase it could be attached to the harness but not physically installed in the car i.e. not screwed into the bung. In that case it would not throw a code becuase the car knows that it is there but it is going to give very false readings possibly the cause of your problem.

 

x3

 

No, the CEL will come on. When I did my header install I forgot to plug the hanress to the O2 sensor and I did have a CEL come up. Turned it off, replugged it, CEL went away on start up.

Did you happen to cut any of the wires on the O2 sensor?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dimi &raquo;</TD></TR><TR><TD CLASS="quote">No, the CEL will come on. When I did my header install I forgot to plug the hanress to the O2 sensor and I did have a CEL come up. Turned it off, replugged it, CEL went away on start up.

Did you happen to cut any of the wires on the O2 sensor? </TD></TR></TABLE>

If he cut the O2 sensor wires, then his CEL would come up too.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dimi &raquo;</TD></TR><TR><TD CLASS="quote">No, the CEL will come on. When I did my header install I forgot to plug the hanress to the O2 sensor and I did have a CEL come up. Turned it off, replugged it, CEL went away on start up.

Did you happen to cut any of the wires on the O2 sensor? </TD></TR></TABLE>

yeah i had to.

the o2 sensor on the dc header is located futher down on the pipe than on the original exhaust manifold, but i added in new wire, sodderd it, shrink wrapped it or whatever its called, then put some electrical tape over all the wrap. and plug it in. no CEL light or anything.

 

CEL doesn't necessarily come on. In my Integra, it NEVER came on and I ran with an unplugged o2 for months

Check the o2 sensor. If its plugged in and tight, its not your header. The header is nothing more than a piece of metal, it doesn't really alter anything within your engine.

 

Did you wire it correctly? Check the solder joints. I have to extend my O2 harness about 2ft. and had nothing happen to it. Gas mileage stayed the same.

 

Reset your ECU. You changed something with the motor that the computer doesnt understand, so it overcompensates with the fuel for safety. When you reset the ECU, it will "relearn" the motor using all of its sensors.

 

that may work....

 

I think people give too much credit to the ecu's ability to 'learn'. All you did was the header right? No high flow cat or test pipe?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IHateJDM &raquo;</TD></TR><TR><TD CLASS="quote">I think people give too much credit to the ecu's ability to 'learn'. All you did was the header right? No high flow cat or test pipe?</TD></TR></TABLE>

You give to omuch credit to your knowledge. cat/test pipe would make the car run leaner

 

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

You give to omuch credit to your knowledge. cat/test pipe would make the car run leaner </TD></TR></TABLE>

A high flow cat or test pipe would not stop as much fuel that's coming out of the header, so more would make it out the back. The ecu doesn't learn as much as people think, it just makes small adjustments within certain parameters depending on the voltage readings from the sensors. The only situations that will make it change more than just a minor amount, will give you a cel too. http://www.pgmfi.org &lt;-- for all your ecu needs. You should go get on that site. You'll learn a lot.

 

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

A high flow cat or test pipe would not stop as much fuel that's coming out of the header, so more would make it out the back. The ecu doesn't learn as much as people think, it just makes small adjustments within certain parameters depending on the voltage readings from the sensors. The only situations that will make it change more than just a minor amount, will give you a cel too. http://www.pgmfi.org &lt;-- for all your ecu needs. You should go get on that site. You'll learn a lot. </TD></TR></TABLE>

I didn't really read his post, i figured someone had a wideband :/

 

well either way, it couldnt hurt to reset that ECU.

 

alright i'll check arounfd at local shops to see if they can rest the ecu. , and what about a fuel pressure regulator?

would that do anything?

-sean