94 jetta failed emissions need help

[jayb3382]

my 94 jetta failed emissions in Va because of to high of NO ppm. the limit at 15 mph was 907 and it was at 1607. no codes are present. does anybody know what could make the NO level high? also, what exactly is NO? thanks alot

[ctesla]

1 part Nitrogen,
1 part Oxygen;
nitrogen oxide

but enough chemistry, we're here to talk cars.

has your oil been changed? did you do a tune-up? are you running lo-grade unleaded? (of course, at $2-3 per gallon)

if your state of Virginia is close to many I've visited, they usually offer a free re-test within 15 days.

change your oil, and either use synthetic or use regular oil, but run it about 1/2 to 1 quart shy to the emissions station. (less oil, less burn)
also, purchase a new air filter, but don't put it in; throw the old one away, and leave the new one in the trunk. (even a new filter restricts; more air in=more air out)
also, put about 4-6 gallons of premium in the tank (this won't break you, but will assist in running the engine a little cleaner and hotter), and do a highway run BEFORE going to the test station, this will insure the engine and catalyst are fully hot.
this should get you to pass. if not, tune-up time...
...or email me with results or phone number, and I'll call to help on my dime.

hope this helps,
ctesla
ASE cert.instructor
[email protected]