[Brad DeMotte]

Hi all,
Am new to this group, as I just bought a '17 M2 after owning an E46 M3 for 10 years & an E36 M3 for 10 years before that. I'm having a problem passing emissions & would welcome any advice......
The car was modded by the previous owner with BM3 software & a Fabspeed downpipe (with cat). I had the dealer flash the software back to stock, & from what I've read on this forum (& told by Fabspeed) I "should" be able to pass emissions. Since flashing back to a stock tune I've put 1200 miles on the car, but 3 of the readiness monitors STILL haven't reset...being the O2 sensor, the O2 heated sensor & the cat.
My mechanic seems to think it's a software issue, as the monitors should've reset by now. I'd like to think I won't have to find & install a stock downpipe just to pass, but even that may not solve the readiness monitors not resetting.
Any suggestions would be appreciated.....

Thanks,
Brad

[cleveland797]

I am having the same issue. Just flashed back to stock tune and nothing is resetting. I flashed back to stock leaving the DME unlocked, could that be the cause?

[Zeese]

The BM3 flash used, running rich? Lots of burbles? Might need to replace the O2 sensors.

[cleveland797]

I'm trying to get the car back to stock for emissons. Car runs perfect with both Stg 2 91 oct BM3 tune and the stock tune. I drove around yesterday burning a 1/4 tank of fuel and non of my readiness monitors reset...

[bmxcamel]

How are you checking readiness monitors?

[cleveland797]

Innova 3020rs OBD scanner with I/M monitor

[Zeese]

Originally Posted by cleveland797

I'm trying to get the car back to stock for emissons. Car runs perfect with both Stg 2 91 oct BM3 tune and the stock tune. I drove around yesterday burning a 1/4 tank of fuel and non of my readiness monitors reset...

None? Odd.

Regarding the O2 sensors, a bad sensor may not trigger a CEL or throw a code. If the air/fuel mixture is too lean or too rich, the readiness monitors will not be reset. If the air/fuel mixture is too rich, the O2 sensors may be fouled or contaminated preventing proper and rapid adjustments (air vs. fuel).

There is probably a link in this forum to the recommended BMW OBD-II drive cycle procedure? Search here, or in the series of tubes, using these terms: BMW drive cycle smog, or similar.

Keep us updated!

Good luck!

[M2CPhilly]

Originally Posted by Brad DeMotte

Hi all,
Am new to this group, as I just bought a '17 M2 after owning an E46 M3 for 10 years & an E36 M3 for 10 years before that. I'm having a problem passing emissions & would welcome any advice......
The car was modded by the previous owner with BM3 software & a Fabspeed downpipe (with cat). I had the dealer flash the software back to stock, & from what I've read on this forum (& told by Fabspeed) I "should" be able to pass emissions. Since flashing back to a stock tune I've put 1200 miles on the car, but 3 of the readiness monitors STILL haven't reset...being the O2 sensor, the O2 heated sensor & the cat.
My mechanic seems to think it's a software issue, as the monitors should've reset by now. I'd like to think I won't have to find & install a stock downpipe just to pass, but even that may not solve the readiness monitors not resetting.
Any suggestions would be appreciated.....

Thanks,
Brad

Did you get this issue resolved? I’m having a similar issue