I?ve got a customer (niche market car dealer) that I help try to get cars emissions compliant for re-sale in California. This particular car is a 17 Mustang GT that previously had a bunch of mods, they sourced stock OE exhaust, etc and put it back on gas (was e85 previously). I did a map compare and changed everything in there back to stock settings except for the MAF cal as they?re still waiting on the stock air intake assembly. Currently they?re stating that the vehicle will not pass readiness, etc concerning rear o2.
Customer:
?It has no codes and the o2s are reading fine but the catalyst monitor is n/a or turned off and I can?t get the oxygen heater and oxygen monitor to get ready. I?ve tried and tried but they won?t set. It won?t pass like this.?
Customer supplied pic
Anyway, I did a ?write entire? on the back to stock mapping. In California the car can get flagged for a CVN change in the ROM (2006 and later) but that?s not the case here, otherwise I?d recommend a dealer flash to fully rewrite back to VIN/ECU part #/ROM ID. Fortunately for him, he?s got a patient inspection guy but not sure what else could be going on here.
I know this is quite the opposite of what we?re normally discussing but this is the post-tuning side of the game I guess 😒😂