Emission testing 90 Q45

[Q45tech]

Recently sold my car's registered home and now it must be emission tested annually. Always exempt for previous 20 years in a remote N. Ga county.
25/25 HC 35ppm allowed 130
CO 0.02% allowed 0.83%
NOx 323 ppm allowed 905

50/15 TEST
HC 18 ppm allowed 134
CO 0.01% allowed 0.75%
NOx 450 ppm allowed 990

CO2 + CO 14.7 on both tests

So much for a 20.6 year old car's first emission test after 327,000 miles.


Remember 1994 saw a tightening of allowed numbers by ~ half along with different cats [more fragle] from 90-93 robust units. Unfortunately I must do the testing for at least 2.5 more year [when I turn 65] or until the Q turns 25 years old 2015.

I was joking with emission test owner that my car had tires that were worth more than the vehicle.

[WesQ]

For comparison, the following are the test results taken 7/2009 for my 1994 Q when it had 41,000 miles.

M1 test at 15 mph
1445 rpm, 12.9% CO2, 1.7% O2, 31ppm HC (80 allowed), 0.26% CO (0.46 allowed), 118 ppm NOx (679 allowed)
M2 test at 25 mph
1327 rpm, 13.0% CO2, 1.5% O2, 4 ppm HC (45 allowed), 0.00% CO (0.42 allowed), 321 ppm NOx, (683 allowed)

Unfortunately, CA dropped the rolling exemption and fixed it at 1975. So, I will always have to test my Q and it will get more difficult to pass in hte future as CA keeps adjusting the pass values down in an attempt to get rid of old cars.

Question for you. Do you think the big drop in HC and CO for the 25 mph test is a result of better manifold vacuum or the drop in rpm?

[3Q Jay]

Tech-impressive if you still have the original cats. HC is low so i'm sure you flogged it and held 2000 rpm until going on the rollers.
NOx is a bit higher than i would have expected though---time for the roto-rooter?

[Q45tech]

Actually I drove it the mile from T3 and let it idle for 15 minutes before the operator put it on rollers but it was warm from the 10 mile trip to T3 an hour previously.

The lower the HC, the higher the Nox........too lean.

90-93 Q45 have only 2 way cats, so zero NOx improvemnt vs 94 and newer.