California Smog and Stratified Tune

[RBYM]

Has anyone tuned their fiesta st in California with a stratified tune and went back to stock tune using their accessport and passed a STAR CERTIFIED SMOG legally? My only mods currently are a Cobb drop in filter, cobb rmm, coilovers and wheels.

I want my car to pass smog legally year after year as long as I can revert back to stock tune and pass smog check and Star certified smog.

Thank you.

 

[RBYM]

Bump

 

[Dialcaliper]

You absolutely must flash back to either stock, or a carb legal tune (Cobb Stage 1 or 2), and drive around until all the readiness monitors have passed in order to pass California smog check. Easy peasy.

I can verify that the Cobb tunes pass as I just passed with Cobb Stage 2 v506 loaded on about 2 weeks ago.

The ECU checksum verification during the smog test is finally active as of 2024. It took them several years to actually implement it after announcing in 2022 which is why people got confused about whether it’s a real check or not. If you try to test with Stratified, Dizzy Tune+ or any other non-approved tune, you will fail and get a mark on your car’s record and need to retest (and might have to visit a STAR station the next time)