Failed HC emissions!

Bourdin, Vincent
Tue, 1 Apr 2003 08:56:05 -0600

Hi all,
Last week-end my 92 NX2k with 110k miles failed HC emissions! Here are the
  Reading Limit
HC 02.12 01.20 Fail
CO 10.55 20.00 Pass
NOX 00.81 02.50 Pass
Looking in the achieves, I mostly found info about NOx related problems, but
not much specifically about HC.
Looks like I'm doing ok with NOx although I have no idea (yet) how my EGR
system is doing. I did find couple of cracked hoses between EGR components,
which I fixed, but that should not affect/improve HC level, right?
Regarding HC specifically (unburned fuel?), looks like I should check all
these sensors: O2 sensor, MAP/MAF, TPS, RPM, and CTS. Since I've only had the
car for 2 years, I don't know what shape they're in, and will test them before
changing them if needed. My guess is they are stock!
As part of my spring clean-up, I also plan on doing TB, Fuel Filter, plugs,
oil/filter, PCV, etc ...

Is there anything else you guys suspect could be wrong?

Also, I'm now thinking that my car was probably not warned-up enough for the
test, could that have played a role in the failure? Keep forgetting how cold
it is in Boston!