Failed Emissions test

Hey guys…i was just wondering if anyone had any tips for me…First thing, i took my car for an emissions test, and i failed my test. The test was taken July 8/02 and the results were as follows:

HC ppm Limit: 86 Reading : 20 Result: Pass

CO% Limit: 0.48 Reading : 0.42 Result: Pass

NO ppm Limit: 0984 Reading : 1555 Result: Fail

I’m guessing it’s not the catalytic because i had it replaced in June of 2000 ( which was my last emissions test, which i failed the first time as well)

The O2 sensor is brand new just replaced July 6/02

I had the timing retarded a bit

Does anybody have any idea’s as to what the problem could be, or does anybody have any tips i should follow to help the test scores…any help is appreciated…and thanx in advance

Your engine is running too hot. What heat range spark plugs are you using and what fuel pressure?

Thanx for the reply Dan…I don’t remember what heat range spark plugs i have in there right now, however i will check later on tonight…in the mean time could you maybe explain to me what the main contributor to the nox levels being so high?

Lots of things can cause NOX to be high, but the usual suspects are too hot of a spark plug, too little fuel pressure or clogged/dirty injectors, timing too advanced. I would try using a colder plug first and then retard the timing a bit more. Hope this helps.

i wz suprised when i failed my 1st emissions test when i did a full tune up about a week before , i had to pay the guy extra $$ for him to past me… i failed because i had that stupid lil air breather thing on my valve cover…

i failed too. but it was the first time i brought my car to the shop when i got it. they test it without me telling them too. it was going to expire in a month. oh wells i didnt pay anyways. think it was having no cat that caused it. not sure and i didnt bother to fix it. just left it straight. i just go to this place and they hook me up with a pass. tired of the city trying to rob u here and there.

The plugs i’m using right now are NGK R BCP R5E 11…Are these plugs ok? Or do you recommend using another type?

Do you have a GS-R? Because that number is not an LS spark plug. Do yourself a favor and run a BCPR6E-11 or BKR6E-11. If you have an LS run a ZFR6F-11. Hope this helps.

:Edited:
Oops…my bad. That number does cross references to a 90-91 LS. So if you have a 90-91 LS, run a BCPR6E-11. If you have a 92-93 LS, run a BKR6E-11. Both of these are a 1 step colder plug.

do you have an auto? if so check the egr valve or vac hose on the egr. if not make sure the coolant is full and the fans are working. also how many miles are on your car b/c it could be carbon build up when i first got my car i failed emisssions b/c of nox. i did a carbon clean and my egr vac hose was all deteriorated so i fixed both and breazed through the emissions. luckt i have a emissions license and waiver license… gl

Well, i have a '91 GS 5 SPD with 187 000 KM’s…Thanks Dan i’ll try the spark plugs, i’ve also dumpped in this stuff, it’s some kinda formula you add to your gas tank, and they claim the car is guaranteed to pass emissions??? also, i’ve put in higher octane (94) maybe that will help too???

i have a little trick for ya thats gunna cost you $1 garenteed to pass ya. worked for me, you had a reading of 1555, i had a reading of 1695 and this worked for me. first make sure your runnin 93 in the tank and brin it down to a 1/4, go to the store and grab two bottles of rubbing alcohol(the highest percent you can find, probably 70%). take a bottle and a half and dump it in the tank. drive around for a couple minutes then go down to emissions. i garentee you will pass. make sure when you leave emissions tho you go right to a gas station and fill up with some 93 or better octane.
good luck

Thanks for the reply guys…i used some of the tips given to me, and i finally passed on the third try… What i did to pass was retarded the timing all the way, i used higher octane gas (94) i re-gapped the spark plugs, added a new fuel filter, and i also used the guarantee to pass formula sold at Canadian tire. Third lucks’ a charm…Thanks again guys!!

Originally posted by Holden Mc Groin
Thanks for the reply guys…i used some of the tips given to me, and i finally passed on the third try… What i did to pass was retarded the timing all the way, i used higher octane gas (94) i re-gapped the spark plugs, added a new fuel filter, and i also used the guarantee to pass formula sold at Canadian tire. Third lucks’ a charm…Thanks again guys!!

If it happends again, drill some air holes in your cat :crazy: