Simply, I got HFC installed (Kinetix, which are supposed to be SES/CEL friendly). One of the O2 sensors is seized and won't come out of the stock cat. So I ordered a replacement from Amazon. Looks exactly like OEM. Before I received the replacement, I drove a couple miles here and there, needless to say, the SES came on. I replaced the O2 sensor and been driving around, 200 miles or so, but the SES is still on. Do I need to reset the ECU? (I have a UpRev tune, will resetting the ECU screw that up?). What should I try next?

 

osiris tuned. that's your last bet

 

Thanks for the feedback. To clarify, a new tune will clear it up? I've already got a uprev/osiris tune. But now I have HFCs, a new cat-back exhaust, and now I'm pumping California 91 octane gas So I'm probably due for a new tune anyway.

 

Resetting the ECU won't mess up your tune. Resetting the ECU will most likely take care of the light - you should always reset/clear codes after at attemping your "fix," otherwise the light will stay on. Depending on the problem, the light will go away after the fix, but not sure about o2 sensors being par of that.

 

Should of had Hills retune you for 91 before you moved. What codes are you getting and did you have to solder wires on your new O2 sensor? Crossed wire maybe?

If you plan on a retune have Hill's email you a copy of your tune so the new shop is not starting from scratch and have a base to start from.

A new tune may clear it up depending on what your codes are remember you are tuned for 93 so your timing/ fuel too aggressive for 91 so you may be running rich or lean in one bank or both.

 

Yeah, I hear ya. Frank warned me about this 91 gas Since all this happened at the same time, it's hard to narrow down what's the cause. I'll have to swing by Autozone and have them check the code to make sure it's not a hardware (bad O2 sensor, package was opened from Amazon) issue. Then I'll go get the car retuned.

Thanks for the feedback.