So i got my whole exhaust done, longtubes, o/r prochamber, and catback about a week or 2 ago. I originally did not buy MIL eliminators because i planned on getting a tuner and just disabling them so when the check engine light came on i pretty much ignored it as much as i could till it stared me down enough to go buy MIL eliminators. I installed them on the rear O2 sensors and had the car off for more than an hour. The light still came back on so i went to advance auto parts and had them read the codes and i wrote them down.

p0153 - O2 sensor CKT slow response (bank 2 sensor 1)
p0133 - O2 sensor CKT slow response (bank 1 sensor 1)

i did some research and i have some questions.

Since the codes are for both front O2 sensors, I doubt both my front sensors went bad at the same time. Also when i got the car the guy said he just had the replaced the o2 sensors. (i could be wrong)

1. one possible reason is an exhaust leak. How do you check for exhaust leaks? Will a shop do it and fix them for free/pretty cheap? (im a college student and dont have the tools to do it myself)

2. I read that it might be a problem with my longtubes moving the O2 sensors back taking more time for them to heat. how do you fix this problem? i read something about a tune? Like i said i was planning on getting an SCT tuner, will this be able to fix it?

3. Its not bad for the car if i keep running it right? i have a 350 mile trip back to dallas for x-mas break.

Thanks in advance for help.

 

If its a substantial leak, you can get under there and find it yourself. If its on the heads, it will destroy them, and you would be able to hear it, if its big enough to make a huge difference, you will notice your shift boot will get warm when you drive for a while, and you will pop when you tach it out.

I run the same setup, and just used extenders and had no problems, with no tune. Although long tubes move the 02 sensors back, the individual primarys would allow the exhaust to hit the 02 sensors faster.

I had to run my long tubes for a bit, and get under the car and flex them so that they cleared the body enough to make me happy, and to get rid of the ratchet steering...

anyways, your exhaust most likely has been beating the crap out of itself everytime you get on it, check to make sure your flanges are tight. I know from running it you cant hear anything when your on it.

 

*bump*

 

It's normal with longtubes. The o2's go thru a test cycle which they need to heat up in the first few seconds after start up. With longtubes it moves the o2's further which takes longer for them to heat up.When you get your tuner you can turn off the test and the light will go away.

 

There is a table in the tune, O2 Transport Delay, that defines the amount of time (in seconds, 0.133 to 0.758 in the OEM tune) that the PCM should expect to see a change in the AFR after it changes the injector pulse--at various load and rpm ranges.

Making these values higher will fix the LT header problem.