I purchased a clean 1988 Oldsmobile Cutlass Supreme Classic but having issues with the smog test with high Nox the funny thing is that I passed the pre smog minutes before with a Nox reading of 198ppm these are things I've done to the cutty so far New egr valve, complete tune up, e3 spark plugs, oil change new cat, adjusted carb, adjusted timing, premium fuel, here is a picture of my smog test any info would be highly appreciated thank you
failed smog check please help
- Thread starter eastman559
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High Nox usually means running lean. Check for vacuum leaks, carb set correctly, recheck that timing is correct and distributor advance is working correctly.
other causes are EGR and Catalytic converter issues, but since you replaced those, less likely, make sure the EGR is functioning and that the EGR ports in intake are not plugged up.
other causes are EGR and Catalytic converter issues, but since you replaced those, less likely, make sure the EGR is functioning and that the EGR ports in intake are not plugged up.
While you are at it get a new O2 sensor from AC Delco, don't cost much.
DO NOT use a Bosch or any other aftermarkets...
DO NOT use a Bosch or any other aftermarkets...
I hope the new EGR valve is a AC/Delco one, the aftermarket valves all have the incorrect generic return springs.
A buddy told me the Egr valve comes with washers the determines how much the rod opensbi wasn't aware of this
I have been consistently and repeatedly disappointed to find myself in situations because of auto zone parts. I would highly suspect that if you got a AC Delco or just snagged one off a junker you would find that the auto zone part was completely ineffective or the wrong part to begin with. PS, duralast my *ss; a jack from auto zone came flying out from under a car at least 300 pounds below its weight rating the other day. It was only the second or third time it had ever been used and it wasn't even 2 years old.
Good luck trying to find an NOS EGR valve, they are pretty rare.
You might be better off just cleaning up your old one if it's not too caked.
You might be better off just cleaning up your old one if it's not too caked.
I had one of those one-size-fits-all with the washers and it never did work right. Try getting the correct one and I'm sure the car will pass. All your other measurements look spot on, so the motor is otherwise healthy.
I got a AC/ Delco EGR valve from Rockauto.com http://www.rockauto.com/catalog/moreinfo.php?pk=87874&cc=1056338
Any replacement part that comes with adaptors is best left on the shelf since they are a red flag, proper replacement parts normally don't use adaptors. There are many different grades of replacement parts and often the good ones have to be special ordered off the internet or the dealership. Chain stores like Autozone are only good for basic stuff like oil and filters, anything more envolved requires going somewhere else.
Any replacement part that comes with adaptors is best left on the shelf since they are a red flag, proper replacement parts normally don't use adaptors. There are many different grades of replacement parts and often the good ones have to be special ordered off the internet or the dealership. Chain stores like Autozone are only good for basic stuff like oil and filters, anything more envolved requires going somewhere else.
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