2017 Mustang GT, return to stock but oxygen sensor won?t go ?ready?

[r2r]

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 😒😂

[r2r]

Sorry for the awful formatting. Posted this from my phone.

[mstang_man]

Sorry for the awful formatting. Posted this from my phone.

once all the DTC have cleared the you need to drive it 90-100 miles for relearn. Unless the switch is still disabled in the tune file.

[r2r]

Nah I did a map compare and copy/pasted every applicable table or DTC toggle against a factory stock 17 GT map. There is no segment swapper tool for this car or I would’ve used it for simplicity. Absolutely nothing left untouched, other than the MAF calibration which has to stay that way til they have the factory intake. They do this often, this is just the first one that I’ve seen with this issue.

[JuiceNA]

If you have a monitor that is N/A and should be available (cat) something is still not back to stock. On my 13, there are 2 settings under OBD2 that affect how many monitors are available. I have no hands on with a 17, so that's all I got.

[decipha]

You should never try to return it back to stock by copying changes over there could be thousands of parameters changed that you dont have access to.

best bet is to just write a stock file to it

[r2r]

You should never try to return it back to stock by copying changes over there could be thousands of parameters changed that you dont have access to.

best bet is to just write a stock file to it

Well I agree with your last sentence. But that’s hindsight now. Guess I could do it all over again. But to your initial point, anything is possible but I’ve personally never had an issue with this method. Sucks that HPT isn’t more helpful with info or I’d ask lol. I do understand their position

[r2r]

If you have a monitor that is N/A and should be available (cat) something is still not back to stock. On my 13, there are 2 settings under OBD2 that affect how many monitors are available. I have no hands on with a 17, so that's all I got.

Actually you know what, there’s an added oil pressure sender aside from the MAF cal. I don’t think it would affect the monitor but it’s not stock and is currently toggled on. Who knows but may be worth removing

[JuiceNA]

I don't believe that switch is the reason.

I have experienced those 3 monitors not completing, no faults set no matter how long I drive the car.
I have seen this on all 3 of my OBD2 Fords. The cat monitor is either NA and O2 monitors will not complete, or cat monitor available and all 3 will not complete. Even from just running a canned tune.
I wish there was more info on this, as I have chased those 3 monitors since my swap was first fired.
I have 2 strategies available to run, Stock and control pack. Both behave identically when it comes to the monitors.
Good thing I WFH and my car is exempt. lol