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Aug 18, 2012 | 04:22 PM

#21

1mustangmaniac

Joined: Aug 2012

Posts: 1

From: missouri

02 sensor problems with bbk long tube headers

I have a 2008 gt/cs with a tune, cold air intake, under drive pulley, bassani
axle back , i have recently had bbk ceramic coated long tube headers install with a shorty x pipe with high flow cats. The problem is that the check engine light keeps coming on. the code turned out to be for a bad o2 sensor......basically it wasn't reading that sensor at all. Well i had it replaced a couple days ago and all was ok. Just today the check engine light is on again! I read another forum and it said the ecm tune has to be changed. I wanted to know if anyone else has had this problem, and what the solution is? If there is one. I would appreciate any advice you could give me. Thanks

Aug 18, 2012 | 07:59 PM

#22

JCON

5th Gear Member

Joined: Jul 2009

Posts: 2,215

From: Delaware

You need to get a tune. With a tune you can turn off the rear O2 sensors altogether or you can tune it to have the proper warm up time.

In the end, your only solution is to get a tune for longtube headers

Aug 20, 2012 | 12:14 AM

#23

808muscle

5th Gear Member

Joined: Oct 2009

Posts: 4,752

From: Maui

What I understand with those headers is that the position of the o2 sensor has changed and interprets the info wrong so it trips the cel. Get a tune from brenspeed or one of the other respected tuners.

Aug 20, 2012 | 10:13 AM

#24

S197GT07

5th Gear Member

Joined: Jan 2009

Posts: 2,662

From: Mass

Quote:

Originally Posted by Argonaut

Interesting - have you actually "passed" the emissions test with your long tubes and O/R X pipe?

According to this site (http://www.nydmv.state.ny.us/vehsafe.htm) NY requires the OBD-II test on all 96 or newer vehicles. From what I understand this test would be very hard to fake. The testing station hooks a computer to your car and it sends the results along with VIN directly to the state DMV. So what am I missing? Who is that "sombody" you know?

Whether or not a car with long tubes can pass the OBD-II test is a confusing subject. There seems to be lots of mis-information out there. Most tunes will turn off the rear O2s, doesn't this result in an OBD-II "readiness" test failure? I'd like to hear from someone with long tubes andcatted mid-pipe who has actually passed the OBD-II emissions test, without having to "know" sombody.

I'm in mass and we have the same OBD-II Type inspection. The part of "knowing" somebody won't get you by the readiness checks. If you fail you fail, no questions asked.

However, if your dyno tuner knows what they are doing, you can have the car pass the readiness check without cats. I've been running the same tune the past 2 years and have passed 2 times.

You are correct about the O2's, if you have them shut off, which 99% of tunes do so you don't get the CEL, you will fail the OBD-II part.

I feel the misunderstanding out there is people that don't know what they are talking about. It's pretty clear cut when it comes to inspection with OBD-II checks:
1) Visual - This is where knowing the guy helps
2) OBDII Readiness check - Your O2's have to be turned ON to pass. To pass without cats:
2a) Fiddle around with the "spark plug non foulers" which sometimes work
2b) Get it tuned by somebody who knows what to do.

Clear as mud right? Feel free to PM me with any more questions.