Will a smog test invalidate my tune?

[BarryJI]

I confess, I am very worried about this. For the first time, my low-mileage 2015 SULEV BMW M228i requires a smog test for registration (in California). The car has a Stage 1 Dinan piggyback engine tune. I do not want to flash the engine back to stock and have no idea how I would ever reinstate this engine tune so many years after Dinan has ceased to manufacture it. Can anyone offer me any reassurance, please? I am horrified by the thought of losing my tune, which has been flawless from day one. Thank you.

[E36 Em Tree]

If you're in CA you're gonna fail smog without a CARB sticker for the tune. If you do have one you'll be fine.

[BarryJI]

If you're in CA you're gonna fail smog without a CARB sticker for the tune. If you do have one you'll be fine.

I think I'm ok because it's a piggyback tune. That does not replace the ECU firmware, it just tweaks environmental data sent to the ECU.

[E36 Em Tree]

I think I'm ok because it's a piggyback tune. That does not replace the ECU firmware, it just tweaks environmental data sent to the ECU.

From what I've been reading it seemed like any modification to an ECU would be detected by the SMOG station now. Im not sure how a piggyback tune works for SMOG but i'd assume CA would do the most and test for any ECU mod. I've resorted to not even touching ECU tunes for my cars now. CA doing CA things... trying to take the legal cars off the road but dont care about the beater cars that havent paid reg in 5 years, have no cats, fenders or bumpers.

[BarryJI]

From what I've been reading it seemed like any modification to an ECU would be detected by the SMOG station now. Im not sure how a piggyback tune works for SMOG but i'd assume CA would do the most and test for any ECU mod. I've resorted to not even touching ECU tunes for my cars now. CA doing CA things... trying to take the legal cars off the road but dont care about the beater cars that havent paid reg in 5 years, have no cats, fenders or bumpers.

I'll let you know later today; I'm going to bite the bullet and take the car to a smog shop recemmended by my tuner. The test, I gather, can identify the deletion or overwriting of certain identifying numbers in the ECU's firmware but cannot see a piggyback as it does not flash the stock ECU settings. Fingers crossed.

- - - Updated - - -

https://www.thedrive.com/cars-101/41...tune-flash-faq

[E36 Em Tree]

Wouldnt the SMOG place visually be able to see the piggyback tune plugged in if they looked close enough?

[BarryJI]

Wouldnt the SMOG place visually be able to see the piggyback tune plugged in if they looked close enough?

Yes but it’s not the product itself that’s illegal, it’s the engine output. I just passed! It raised no red flags and the guy was great. My assumption was that piggybacks would be ok but at the beginning he said “not necessarily”. However, when he saw it was a Dinan tune and all the output values checked out he said it would have been very unlikely to fail. Now I worry a little for all the guys on this forum who teased me eight years ago about not being more aggressive.