Ok so i got a check engine light on and i went over to AAP. They did a scan for me and told me it was the Catalyst system efficiency below threshold, and the computer did not say if it was bank one or two. SO I have 3 possibility's. Bad CAT, Or One of the O2 sensors is bad. Anyone out there experience this yet? I have a 3'' exhaust setup all the way back. But stock headers. I did not setup u this exhaust system so i know little about it. But anyone out there with any info, PLZ help.

 

Test pipe? If so you need to do a search and read how to fix it. Sweet mother of mary this post is right under yours lol. I cant make this **** up!

https://www.evolutionm.net/forums/ev...-question.html

 

here's a video to make it easier.

http://www.youtube.com/watch?v=qoAkDnwP60c

 

Get an O2 extender for the rear 02, like this for example...

http://cgi.ebay.com/ebaymotors/O2-ex...Q5fCarQ5fParts


The reason for the Cat eff is that the difference from front and rear 02 is not much.

 

Or you could go to Autozone or Advance Auto and get 2 spark plugs anti-foulers. Those did the job for me.

 

Be more descriptive? How does it work

 

You think this is my problem? Why do you say to get this.

 

Here are detailed instructions:

https://www.evolutionm.net/forums/ev...cel-light.html

 

Thank you Dacib, Im still excepting all other ideas or experiences.

 

I run a test pipe and two spark plug anti foulers drilled the top one out. works great no check engine light. and the test pipe gave me the extra spot for my wideband 02

 

Ok here is the picture of the O2 on the test pipe. ( SO is this my problem?) I was wondering is it damaging anything since its saying check engine. Is it maybe running to lean or rich.

 

I don't know but the picture looks like the two wires are cut,fuzzy picture though

 

Ill double check that right now

 

The reason it did not show what bank on the code results, is because a inline-4 only has one bank.

I firmly believe that the test-pipe is causing your CEL to come on.
If you get the sensor out of the main stream exhaust flow, it will think the catalytic converter (that isn't there) is doing it's job.

My hollowed cat causes the same problem, but I'm too lazy to do anything about it, instead I just use my scanner to clear the code when it comes up.

Good luck!

 

So you all believe i have a 50/50 chance of fix this problem.