I recently went through a failed e-test also. First, it failed on NO at 40 km/h, and then upon retest about 1/2 hour later, it failed on everything else other than NO at 40 km/h.

Without changing anything, I put in Sunoco 94 and drove it on the highway for 20 minutes before going in. It passed. Frankly, I don't consider these tests to be too accurate (even the Ministry guy was saying the same thing).

Truthfully, if I were you, I would try the above and go for a retest - it'* only $17.50. If the O2 sensor is old and you are planning on keeping the car, replace it also (it'* only $50). Even if it fails, you can go for another retest at $17.50.

I have no idea what */C effect would be, though.

Good Luck!

BonneMeMN

I finally got the supercharger working.. changed both belts, water pump and that bearing on the center idler pulley ( that Crappy Tire didn't have a replacement for as far as the whole pulley.. Gm only parts? ) oil change and supercharger fluid flush ( and GM guys aren't right.. 1 bottle doesn't do it.. I put 2 bottles in there.. with a dribble left in the bottle to spare.. and P.*. they smell awful and mental note.. do not have any on your cuts wounds and or busted knuckles as they sting like PITA ) so needless to say that was a 13hour job.. including breaks dinner.. out for a drive.. some Video game times.. hee hee..

So I don't need an exact tempreture to test the cat?? Just as long as it'* around 100F above the pipe before the Cat???

So cleaning the EGR is straight forward, but I heard there'* something to do with squeezing 2 bolts or something at the bottom of it.. and the part I'm confused or don't remember is if the car stalls does it mean the EGR is good or bad??

$50 a piece of O2 sensor.. humm.. well thats $100 I really don't want to spend if I can get away with it for now.. spent a lot already

$17.50 for the emission test ?? I've always been payin $35 Where'd you go to get so cheap?

P.*.*. Thanx for all the info guys.. keep it coming.

Something makes me think it'* not the O2 sensor. CO is caused by a rich condition, and NOx is caused by a lean condition (extra heat, dissociation and the like). With a bad 02, it seems like you would have more of one, and not the other. Which leads me to the cat. The EGR, I dunno, nor do I know how to diagnose a bad one.

BTW, only the front 02 would have any affect on emissions. The rear just monitors the condition of the cat.

The cat can get as hot as 1600* F, apparently; but I'm sure it'* particular operating temperature depends on the amount of the reactions happening inside it, hence the "before cat" and "after cat" temp. check. If the pipe leaving the cat (not the cat itself) is 100* F hotter than the pipe coming into the cat, the CO and hydrocarbons are being burned at least somewhat correctly.

-b

Drifter, the original test is $35. If you fail, you can go back to the same facility for 2 retests at $17.50 each. There are some time conditions also (I think 60 days) - www.driveclean.com gives you all of the details.

I have heard where if a car was not "thoroughly" warmed up it can cause you to fail. If you had to wait your turn to get in, leave the car running and keep it warm.

I believe that by simply going for a ride on the highway for 20 mins made a big difference, may not have been the gas.

How long/many miles since you got the */C going again did you test? The PCM will need to re-adjust. It'* probably best to reset it, pull the battery cables off for over 30 min.

yes.. the owner took it out for a drive for it to warm up then did the test.. I was waiting bout 20min + before my car went in.. I will look into leaving the car running next time. The supercharger belt was put back in sunday.. and I did the test monday.. so that might be contributing to it as it seems much better now after driving for a while with the */C. I notice a lil hissing when I hit boost which I'm stayin away from for a lil while till I'm sure the rust and everything else is cleared up in the cylinders. I will post that on a different topic.

I didn't know it'* cheaper to retest as this is the first time I failed.

I still haven't had a chance to check the temp of the CAT.. but I will do that this weekend as I will tear the EGR out and clean it.. by the way.. anyone know where it is on the L67 series II ?? I know it should be near the TB but if someone has a pic to show me that would be great.. As for the CAT.. I thought the unburnt fuel may get burnt before the cat and thus the manifold and such would be hotter then the cat ?? and SHOULD the cat run hotter?? ( meaning it'* either too rich or too lean?? )

Thanx for all the help guys.

Not sure what you mean, exactly. Unburned hydrocarbons and carbon monoxide should be burned (oxidized) in the cat, not in the exhaust manifold. Since the oxidation reaction releases energy, the temperature of the cat exhaust gases should be higher than the cat intake gases. If they're not, the oxidation reaction isn't happening for whatever reason -- too little oxygen in the exhaust gases, poisoned catalyst, etc.

Cat oxidation is a lot like combustion; if the exhaust gases from the engine are too rich, the cat won't be able to burn all of the HCs and COs, since there won't be enough oxygen in the exhaust, hence you'll get high HC / CO readings. If the exhaust gases are too lean, the cat should be able to take care of the leftover HCs and COs (since there'* lots of oxygen), but you may get high NOx readings.

Regardless of whether you're running rich or lean, though, the cat exhaust should still be hotter than the cat intake if the cat'* working correctly, unless by some miracle your engine doesn't exhaust any unburned hydrocarbons or carbon monoxide.

-b

k.. that makes sense.. thanx.. will check that this weekend.