my 91 won't pass CA Smog, Nox fails? - ZR-1 Net Registry Forums

zora1 · 01-07-2004

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

bans25 · 01-07-2004

Quote:

Originally Posted by zora1

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

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

zora1 · 01-08-2004

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.

bans25 · 01-08-2004

Quote:

Originally Posted by zora1

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)

zora1 · 01-10-2004

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.

Locobob · 01-23-2004

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.

Patton · 01-25-2004

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.

bans25 · 03-03-2004

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

Wayne · 08-21-2004

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

FU · 08-21-2004

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

01-07-2004	#1
zora1 Join Date: Jan 2004 Location: NorCal Posts: 3	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

01-23-2004	#6
Locobob Join Date: Jan 2004 Location: Portland, OR Posts: 1,047	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. __________________ Robert ZR-1 Net Registry Oregon State Director 91 ZR-1 #431 Black/Black LPE 368

08-21-2004	#9
Wayne Join Date: Aug 2004 Location: Sacramento CA Posts: 22	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

01-08-2004	#3
zora1 Join Date: Jan 2004 Location: NorCal Posts: 3	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.

01-10-2004	#5
zora1 Join Date: Jan 2004 Location: NorCal Posts: 3	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.

01-25-2004	#7
Patton Join Date: Dec 2003 Location: Sacramento, CA Posts: 220	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.

03-03-2004	#8
bans25 Join Date: Dec 2003 Location: Dover Posts: 54	I believe it was Hib that had wrote about the "emissions" EEPROM

08-21-2004	#10
FU Join Date: Mar 2004 Location: Found Member Posts: 4,327	High NOX ? Are you guy's using the stock chip ?