I'm kinda new to the whole "mechanic" thing, normally my ability for repairs/work is that equal to my funds

However, I recently got my S2000 with a testpipe and CEL fix on it (so I was told) and after about 2,000 miles and owning it for two months I got a CEL.

Its the rear o2 sensor, its running quite rich, at like 1.3 from a cold start to 1.0 after its warmed up, flucuating to .9-1.1 (girlfriends uncle owns a shop and explained this) he blames the lack of a catalytic converter, and explained the damages/disadvantages of not having a cat and said I should look into a high flow cat..

My main question is, how is it everyone on this site uses exhaust/testpipe combination, do you have the same problems? Are their other fixes to keep my car from running rich and/or causing carbon build up?

Thanks all!

 

do you have an AP1 or AP2? AP2s get the CEL way more often with a testpipe, no matter what type of 'fix' is offered.

 

to prevent carbon build-up just go WOT from time to time.

 

I'm running a Ap1, and this is the second time the CEL has come up in roughly a month, it goes away in time, this time I had it cleared..

But Im still confused as to how everyone with a test pipe avoids running rich? Can I get a tune to accommodate having a test pipe?

 

I don't think you will be running rich... From what a honda tech explained to me the secondary o2 sensor does not affect air/fuel ratio. The primary o2 sensor takes care of this. Maybe someone else can confirm this? Which test pipe are you using?

 

See thats my problem, my test pipe brand/diameter is unknown as I just the car 2 months ago and the seller hadn't put it on as he was the second owner and it was the original owner that put it on.. But as far as "running rich" thats what the mechanic said, my volts were reading 1.3-1.0 and he defined it as rich b/c I wasn't burning all the fuel..

He told me in the longrun Im building up carbon deposits and going to burn out my fuel injectors? I dont know if I should be buying a high flow cat, or if I can get a tune to fix this? Really quite confused??

 

Do you have a 2000-2001 S2000? They are know to run rich from the factory (ECU)

 

Yea I have a 2000.... Ok but from what I understand running rich gives alot of problems along with robbing horsepower, so how do I fix running rich?