[M5aud]

I'm in the same situation look forward to knowing if it's the cats as you can get a tune from ess that will remove cel

 

[M5aud]

CEL can be many things but when it states cats inefficiency and O2 sensors it points to either. If the cats are inefficient it doesn't limp mode the car so you can still drive etc but to remove the code you need to replace cats, O2 sensors or remove cats and get an aftermarket tune. My preference is to remove cats and tune the car. I want to know if the op loses the code from the cat replacement as then I can get a tune instead of wasting $8k here in Oz for new headers!

 

[M5aud]

Find the cause of your problems? One member had the whole car reprogrammed and that fixed the problem... Let me know.