Depends on the failure. There are a number of failures that are border line or intermittent that can pass a drive test. In Oregon, all we need to do is pass an OBD test. So people look for ways of clearing a CEL.

On my Passat, it still would pass emission's test, but it on a long drive it would throw a CEL because the fuel compensation percentage was hitting a maximum range. The system still worked, but the closed loop control was way off. That would probably (did) throw off the mixture at full throttle and full throttle is not tested.

I could have cleared the CEL driven it and passed.

I went with replacing the MAF. Car runs better, and get a bit better fuel economy. Long run it may get my converters to last longer.

I feel your pain... I did two turbo engine swaps in California. I had to get tested a couple of times before I got it right. Even after it was legal , the local sops were afraid to inspect it. They were sure it was a CARB operation. Apparently, the CARB will send bogus vehicle's out to see if they get passed. This bit of fear keeps the inspectors in-line.

I see what you mean but he had the car on a Dyno looking thing and gave it full throttle quite few times, even ran at idle for a while and it passed all emissions he said.

Wouldn't a bad MAF sensor or something show up during such a thorough test?

It kills me that I have to go through so much crap over a car that isn't a polluter. I wasn't so mad when I couldn't get my 78 Power Wagon with an RV cam to pass decades ago but this car is a stock four banger with under 98,000 miles. <img src="/forums/images/graemlins/rolleyes.gif" alt="" /> A lawnmower with bad rings is more of a polluter. <img src="/forums/images/graemlins/lol.gif" alt="" />

CARB Link

You'll love my funny Chris. In WI we have emissions testing, only, if your car is older than 10yrs - you don't have to test. Only the new cars do! HAHAHAHAHA! <img src="/forums/images/graemlins/butwiggle.gif" alt="" />

<img src="/forums/images/graemlins/lol.gif" alt="" /> YEa Phil the logic just isn't there......but it does make me want to buy another old Ford pick up with a 390 though.

We have exemptions for older cars too but I think the car has to be free of ant smog OEM.

1975 or older are exempt.

Sounds like readiness flags got you.

Basically, there are several batteries of tests that have to run (and pass) to set each flag. These are also the tests that determine whether or not the SES light comes on.

The only way to run the tests is to drive the car. They run automatically, in the background as you drive.

Since it's a GM car, I have some relevant experience relating to getting those flags to set. Let me know if you need help.

Thanks Clay...I'll be taking it back soon. We'll see what happens from there.

Yup, I was hit by the Readiness Flag issue when I registered my 96SR and posted about it here so no this isn't new.

Maybe you didn't search for it before you posted LOL. <img src="/forums/images/graemlins/wink.gif" alt="" />

Just kidding. Within a few days, I was able to retest and passed. If you read my thread there's also a procedure you can follow to reset them if you don't want to wait. <img src="/forums/images/graemlins/kewl.gif" alt="" />

So you know how I feel then. <img src="/forums/images/graemlins/lol.gif" alt="" />