BMW Detecting Tune

[BPMSport]

Originally Posted by Rekrul

Oh I'm not referring to passing emissions testing.. I don't have to worry about that. I have the Dinan X pipe... and the power is very substantial, especially when paired with the tune.

I meant if you went to the dealer with no check engine light on and a clearly catless vehicle, it would likely raise suspicion and lead to them perhaps flagging your car.

Not necessarily... It takes some time for that fault to be thrown. Multiple starts and mostly freeway/consistent driving. They will see that the cat monitors are not ready if they investigated and then it would look legit.

I think having a CEL there for cats is worse. Regardless, I've never pulled the tune off before taking it to the dealer. It's a waste of time. They can't read or tell that I've tuned it anyway. Out of quite a few tuned cars, never a single issue at the dealer with any of them. The only thing I think may be more of a giveaway is if the cold start is disabled. Everything else they can't really draw an accurate conclusion from.