KuHL 951

Home Depot has the best price. It's not cheap at $15.50 gal but you can use the rest of it to run more boost for at least half a tank of gas.

Bill

944Girl,

That is just crazy. You spend good money to get a brand new as you put it "most restrictive" cat and your NOX goes up!

I wonder. Maybe the cat IS our problem. It could be is restricting the exhaust so much, creating to much back pressure, that the EGT's are getting too high. It would be interesting to do a smog test sans cat (test pipe). Then see if that lowers the NOX. My guess would be that it would. I may try this, since my car is set up to swap the cat with a test pipe.

But to prove how crazy the system is, say by removing the cat, the exhaust is no longer restricted. EGT lowers. NOX is no longer created due to the lower EGT. And heaven forbid, the car passes the rolling test. Guess what, you are not out of the woods. You would fail the visual, because you do not have a cat!

If you see a pristine 951 in Cali with Nevada plates....wave. It will be me, smiling, while flipping the finger to the Smog ****'s.

billthe3

Hurray for stock gutted cats!

ejsaenz

I don't know if this idea would help, but... My 90 k5 blazer wouldn't pass smog, i did a pretest to verify first. (don't wanna get nailed as a gross polluter) . I asked my brother who's a smog tech and he told me to get an oil change then do the smog check. I went to wally mart and had the oil changed. after there, went to the smog only place... It passed!!!

they also did some top-end cleaning(seafoam??) I wonder if adding water with a squirt bottle at the intake would do the same to clear up carbon, it may also be a cause of the problem. it works on my GM trucks...

It's worth a try, maybe thicker oil too???

just another idea.

I've had my share of smog probs on all my cars...one place wouldn't smog the S2 because I bypassed the bad fan switch with a manual switch... darn button pushing smog monkeys.

inactiveuser92616

running E10 may help, it burns cooler. This is gasoline that at the pump says "may contain up to 10% ethanol". E85 will ruin the stock engine, so don't do that. Water injection (done properly) will also help the NOx issues. Anything that will lower your combustion temps. I do not recall if you can change timing on these cars, but backing off the timing some will help too.

PCA 944

I'll post the results from my 1986 944, which had high emissions but still passed. If it makes a difference, I had a tune up immediately before the smog check. Mechanically the car is excellent, except for some exhaust fumes under hard acceleration.