kev951

was your car warmed up enough- the car and CAT need to be hot? was there a fan placed in front of the car during the test? before you change the fqs switch setting, go buy cheap new ngk spark plugs and put in some 100 or 104 unleaded sunoco race gas, when your tank is near empty. Just add
2-3 gallons. Then drive the car on the freeway , get it hot and smog it. If that doesn't work , you can try adding more CO to the mixture to take care of the nox problem with the fqs switch. But, It may effect HC and as a result, Hc could be high and fail but nox will pass. Your HC is borderline. I would need to see the car to be 100%. How many miles are on the car?

xschop

Like Kev says make sure all your O2 sensors and ign. parts are new/good and that your timing is correct then Add 6oz/10gal petro of ACETONE for the test then 3oz/10gal petro daily mix to clear the caked carbon. High temp combustion chamber causes Nox, poor combustion causes High HC.

KuHL 951

The sad thing about those emissions numbers is California reduced the allowable limits across the board last year by about 33% depending on the year/make. It's making any 80's car a nightmare to smog anymore. My son's smog test on an 02 F-150 w/ Triton V8 came in at 1/10 or less than the numbers on a most 944's. The 944S failed miserably this year in both HC and NOx before a certified cat was installed and then it passed very very clean before I sold it. I've given up on older cars for awhile.

fressssssh

It has about 180xxx on it. /:

odurandina

stop running cats, reg in a state without all that nonsense and return home with out of state plates, or setup and run that e-85 crap or buy a real p-car like an infinity G37.


i expecially like that e-85 idea. cool.

fressssssh

FYI: I noticed that my PCV failed on my results sheet just now. I went out to look and the hose connecting it was disconnected. Would that affect my emissions any.?

gtroth

I'd say a vacuum leak from that disconnected hose could effect your NO levels. That's allowing un-metered air in (air through the intake that the DME knows nothing about, so might not adjust the fuel injected properly).
I was coming perilously close to failing NO (1351 measured / 1400 allowed). Then I changed the AFM for some other gremlin I've been running down, and NO went down to 946 measured. So it seems that to get the NO down, DME likes to have an accurate measure of intake air .

clickpilot

FRESSSSSSSH, you are not alone...

My '87 951 has just failed CA smog for the first time. I'm the original owner with 98,000 miles (about 60k on CAT), restored back to stock 6 years ago. Car has been running great for the last few years with FQS set to stock, new plugs, wires, dist cap, speed sensor all done less than 1k miles ago.

15MPH - %CO2=14.5, %O2=0.4, HC=135, CO=0.43, NO=1033
25MPH - %CO2=14.8, %O2=0.1, HC= 43, CO=0.24, NO= 528

HC and NO failed at 15MPH. Car was nice and toasty for the test. This has really put a damper on my day. Any suggestions would be REALLY APPRECIATED!

kev951

almost the same results as fresh, you might have a pcv hose oir some hose cracked sucking in more air. Did if fail for anything else? FYI people, when posting a faile result, post everything that failed, including any VISUAL or FUNCTIONAL failures to help diagnose

clickpilot

Thanks Kev951. I'll double check all the hoses. Maybe I accidentally knocked one off. Car didn't fail for anything else. I remember the last two tests (2 and 4 years ago) passed easily and the cat has less 1k miles in those 4 years.

Mongo

Connect your hose back up and drive the car for a bit so the cats are at operating temperature. Although cat temperature may not be an issue judging by your figures, it's a possibility. High NOx means three things usually:

1) Vacuum Leak
2) Not Enough Fuel (Lean Mixture)
3) Cat Failure

I did 4 smogs on a 928 that failed rich 3 times, then failed on NOx the last time. The cats failed due to the overly rich mixture.