[s-cars] Emissions Q&A

[Sandy Sligh]

Ok, lemme first through out some more thoughts and
concerns i have with high HC:

Here's from what I can gather can cause a rich
condition at idle.

A lean misfire condition caused by goofy PSOs,
Incorrect sensing A/F ratio sensing at idle (02
sensor), Incomplete combustion at idle (plugs/boots),
Improper fuel atomization (dirty injectors), Rich fuel
mapping (software), Correction for a lean A/F (vacuum
leak after MAF? did I get that right?)


Thermostat (engine temps according to gauge were at or
around 90 during testing), Plugs, boots, O2 sensor are
all new.

Concerns:

1) I did notice during the 2500rpm test, the exhaust
note was not smooth (Stromung). Most of the time there
WAS a nice smooth exhaust note but throughout the test
I heard random "putt-putts" (if that makes any sense).
Is this the motor misfiring? Remember, the test was
NOT ON THE DYNO and I dont hear or sense these while
driving. Afterwards, I did and continue to notice that
the same subtle roughness is apparent at idle.
Misfire? Maybe?


2) What has become of the catalytic converter? If
there is unburned fuel making it to the tailpipes,
won't that fuel crap up the cats on the way out?

__________________________________________________
Do you Yahoo!?
Yahoo! Platinum - Watch CBS' NCAA March Madness, live on your desktop!
http://platinum.yahoo.com