Hello - I've been off the list for a while since I just moved from KY to RI. M5 still running great, approaching 120k. Problem is it just flunked emissions, NOx too high. KY didn't require inspection.

Readings were (GPM = gram per minute I think) HC 1.14 vs 2.25 limit, CO 12.99 vs 23.74 limit, NOx 4.61 vs 3.25 limit (FAIL), CO2 495.09 (no limit listed?).

Engine is stock except it has a SS MAF. I actually leaned it out a notch across the range before the test, maybe I overdid it even tho A/F meter shows that car is in closed loop and dithering across the range. They give you a speed vs emission plot for all three. Looks like they accelerate the car from 0-30mph and back down over a 30 sec period, and I see that the NOx spikes during the accel at about 8secs.

So it seems like I ought to richen it back up a click and try again - the CO and HC were well below limits. I have no idea if they warmed it up before the test - it sat there for more than an hour before they got to it, so I highly doubt the cat was very hot. CAT is a DEC, about 6 yrs old.

Anyone have any addiional ideas? I am going to be pissed if it fails the 2nd free test, and I don't have a mechanic around here I can trust.

BTW, anyone know a good mech in the Barrington (East Provicence) area?