p1133 just came up on my car. I have had p0420 for a couple months as the cat went bad and shotvout the ezhaust. I have a CA 3" header and dp for 1 year with no problems. I randomly get a random misfire code and it isn't on now. Is this a warranty claim? I am at 34850 now.

 

Conditions for Setting the DTC
• The PCM detects that the HO2S 1 rich-to-lean counts, or the lean-to-rich counts is less than a calibrated value.

• DTC 1133 sets within 60 seconds when the above condition is met.

Important: The HO2S 1 may be damaged due to contamination.

 

Yeah I read that. Reason I am asking is when I searched a few post mentioned that the header or downpipe may be the cause. I dont want to bring it in and the dealer tell it is from my intake/header/catless downpipe that I have had on for a year.

The cat blew apart two months ago. When I took the dp off 3 weeks ago to look at it nothing was left inside the cat. so maybe it damaged the o2 sensor after the cat even thought the p0420 was already set.