Tupper

For people who live in States that do emissions testing through the OBD2 port, how does one pass emissions with a tune?

One question I have is, if you have aftermarket mods that trigger a CEL that gets removed by a tune, then won’t flashing back to stock before inspection just being back the CEL, hence causing one to fail emissions inspection?

Inquiring minds need to know

detansinn

I had a car with a special map that was designed to get through the car through emissions inspection — ala Volkswagen AG. Car had cams, machined heads, deleted one CAT, air pump delete, and more. The ECU code was altered to pretend that all of that equipment was there and functioning. Aside from one small high flow cat, this was, for practical purposes, a race car powertrain.

Then, one year, I forgot to load the special map and the car passed emissions anyway. 🤣

If it’s running well, not throwing CELs, and you don’t live in California, it’s likely going to pass.

Tupper

I hear that in Illinois the inspector can tell through the OBD2 port that the ECU has been reflashed and can still fail you, even without CELs.

Not sure but I just want to be cautious moving forward doing this, and I don't want to burden M Engineering's thread with this discussion--but it's an important one for sure.

kgs365

just refresh back to stock, get inspection and flash back?

Tupper

^ The issue is if you have aftermarket mods that trigger CELs (sport cats, etc).

Sounds like you may literally need to return all of the equipment back to stock, AND reflash the tune to stock, in order to pass emissions.

So a bit more involved, I am speculating.

Tupper

@M Engineering do have any insights about this?

reddsektor

sport cat does not trigger CEL, you won’t have issues with inspection, just get the tune already

Kitc2246

Cobb advertises that their tunes are 50 state compliant. I understand CA wants to see the ECU sticker from Porsche for the PDK Sport+ "detune".

centaur

Isn't that a stupid thing to prioritize in a state that has overwhelming problems that they have not a clue of how to address. Yessiree, better make sure everything is Kosher in "Sport +". Simply amazing.

CodyBigdog

Maryland does emission tests through the OBD port (no longer through the tail pipe). I did a power bump/flash from Dinan on my M4. Since then, I’ve had no problems passing emissions testing, twice. Whether you pass, or don’t, I suspect is dependent on the software/company you use, and the folks/state doing the emission testing.

When I eventually flash my 992S, I will first see if I can pass the emission test. If I don’t, only then will I bother to re-initialize the factory state.

centaur

Most states connect to the OBD port and look for codes that would involve the pollution stuff. CA supposedly has some whiz bang crap that can tell if you have a non factory calibration.

Tupper

I don’t know what Illinois does.

Doesn’t matter, I’m pretty much settled on doing the tune. Only reason I am waiting now is because my car is garaged till March.

Again, I am doing not just sport cats (which I already have installed). I am doing a whole exhaust with a new set of sport cats. CEL with that just complicates emissions testing down the road—I would have to swap out exhaust for OEM just for emissions, and then put the aftermarket exhaust back in afterward. A pain. Pay to play, I guess

reddsektor

tupper pal, almost no exhaust out there will trigger a CEL whether it’s with sport cats or not. The only thing that triggers a CEL is catless which is what I have and the light/code is tuned out so no issues.

4 Rings

BUY IT!! You’ll thank yourself

John Mclane

The O2 sensors will fail a test without giving CEL, regardless of hardware mods.
Interestingly, the dealers can't tell if the ECU has been flashed or not.
This is not conjecture, the above happened to my prior car with the new owner (by then, CPO).