my 91 won't pass CA Smog, Nox fails?
 

hi
I have a stock 1991 ZR1 with 27k miles. I am original owner, car has been garaged for almost 9 years.
I have put 12k on it since May '02, and it passed CA smog then, but not now?
Smog shop says it failed the NOx and passed everything else.
My mechanic says he doesn't have the equipment to test the NOx.

Has anyone came across this problem while trying to smog their car?

Changed plugs (two had small amount of oil on them, but all looked good - considering they were originals).
Changed fuel filter, it was yucky.
The car burns about a quart of motor oil a week.

Maybe the cat/convertor?

I appreciate any advice! - Thx

Re: my 91 won't pass CA Smog, Nox fails?
 

The car burns about a quart of motor oil a week!!! thats a lot! how many miles a quart?

about 200 miles per quart.

I was using Redline 10-30 until about 5-6 weeks ago, I changed back to regular oil and it seems to burn less.

Because of the weather I haven't driven enough to really tell difference yet.

Thats a lot of oil to burn in 200 miles. Is that normal driving or racing (not spirited driving, but real racing)

No, not racing. Just daily driving.

I may get up to 80-90 mph for a few minutes on the freeway, otherwise its curvy mountain roads or stop-n-go city driving.

Are you sure all of that oil is being burned? I had a similar problem with oil loss and most of it turned out to be leaks. It had me fooled for a while as I never saw a drop of oil on the garage floor. As far as the emissions problem goes I would think you'd have failed on Hydrocarbons as well NOX if the cats were bad but then again I'm not exactly an expert on this subject. I've heard that California has tightened their testing standards since the cars were new, could be an issue here. If I were in your shoes I think I'd check the plugwires and coil packs next. You can also use a pyrometer to check if the converters are working - exhaust gas should be hotter exiting the converter if it's working.

If all ealse fails I seem to remember a post about someone making custom eprom chips to install for smog and then revert back to stock after, its supposed to lower emmissions (and power) drastically. Anybody know the point of contact for that guy??
He lived in cali, as do I and I fear down the line they will try and cage my beast with emmissions crap too.... hopefully we can all overcome these commie smog laws.

I believe it was Hib that had wrote about the "emissions" EEPROM

my 91 won't pass CA Smog, Nox fails?
 

zora1 WROTE:
I have put 12k on it since May '02, and it passed CA smog then, but not now?
Smog shop says it failed the NOx and passed everything else.
My mechanic says he doesn't have the equipment to test the NOx.

Has anyone came across this problem while trying to smog their car?
______________________
Hi zora1
I Have the same problem now that you posted in January. My NOx failed. I am in CA also. Will you let me know what you found out to get it to pass or not, hopefully it was a simple thing. I look forward to your reply.

This is my first try at this, Hope I got some of it right

High NOX ? Are you guy's using the stock chip ?