I have an OEM Catback that I'd be willing to part with, located in the Nebraska area. However, if you're just looking to get rid of a CEL from a catless downpipe, there are adapters that contain a small catalytic converter element to fool your O2 sensor into getting the correct reading, just have to fiddle with them a little to find the correct spacing. Too close or too far will cause the code to remain.
Often called a O2 simulator, I just ordered one from "Big Daddy's Garage". If this sounds like what you're looking for, I can let you know how it works after I bust my cat out this weekend.
Hi. Thanks. I’m interested in both I think. My main concern about using an apdapter/spacer is how would that impact two other things:
1) engine performance/ecu management of fuel/air mixture
2) my ability to pass inspections.
in addition to my check engine light, I’m getting a stuttering/gradations of power when at speed, most notable on highways. My guess is the downpipe/exhaust 02 sensor issue is causing confusion impacting my engines performance including my mpg. It’s annoying snd I want smooth power AND no check engine light problems.
I’m also wondering if the adapter would be noticed and cause me to fail inspections out here. If I sell, I’dbe passing on a potential headache to the new buyer. I want to work this all out. Hence the original parts request.
The upstream O2 sensor is what's used to control fuel and air mixture, the downstream O2 sensor is only used to determine whether the catalytic converter is functioning properly. Pulling the exact code will tell for sure, but typically the issue with going catless comes from the downstream O2 sensor no longer seeing the cat there and thus throwing a code.
If it is the downstream O2 (again, pull the codes to be sure), then adding on the cat elbow will not affect your fuel air mixture whatsoever.
As far as emissions go, it'll depend on how your state does it. If you're catless or have a bad cat (which will throw a CEL for the downstream O2 sensor) then you will fail any smog that checks actual exhaust makeup, like ones that hook up to the tailpipe, regardless of what you do. The only way to pass those is with the proper emissions equipment. Evidently, some states just use the vehicle's own diagnostics to check for proper cat function, in which case adding the cat spacer will actually allow you to pass emissions where you wouldn't before, because the computer no longer sees the code.
If your code is for the O2 sensors, going back to the OEM catback will not fix it. Pull the codes and get back to us.