Used m3 w ESS- Emissions

[jdub486]

I am looking at a used e90 m3 with the ESS g1+ kit on it. The car has stock cats. Someone bought it a few months ago and returned it because apparently it won't pass emissions. Does this make sense for a car with stock cats? Any insight to why it won't pass? I thought these kits were TUV clean and would certainly pass emissions with cats in place. I don't want to buy the car and then have to remove the ESS kit every 2 years.

Do any tuners offer a no boost tune that would pass emissions?

[M3SQRD]

I live in MD and found out the hard way in 2021 that MD is another state that’s added scanning the ecu as an additional test to its emissions testing. Your ecu calibration ID and checksum must match the stock calibration ID and checksum. The only way to do this is to reload your original stock tune to the ecu and then go thru the drive cycle to set all emissions equipment (or just drive normally for a couple of days. I ran into this problem using the DMV kiosk emissions testing machine on both of my e92 M3s and f82. I passed after reloading the stock ecu tunes, driving back to the DMV and retesting with the kiosk machine. All three past emissions testing. Drove home and reloaded my stage 2 tunes on my e92 M3s and stage 1 tune on my f82. Then later in the week I reinstalled the Akra EVO and AA x-pipes with HFCs on the M3s.

[Soden82]

Depends on the state I think. MA does the same thing now, so even a tuned car will get flagged and not pass inspection.

[Oreo Cat]

ess g1 comes with a smog specific tune that is only used for smog check