I did my drive clean test tody on a 98 SL1 Saturn.



I changed the oil, plugs, wires and air filter.



Ran the car for a half hour on the highway and failed.



My NO ppm came in at 1003 and the limit is 505.



Can anyone offer any suggestions?

My first guess is that the EGR valve is stuck closed (a good/bad thing), allowing combustion temperatures to rise generating more NOx than the catcon can handle. Usually the EGR valve stays open more than necessary and contributes to stalling tendencies, hesitation, andstumbling. A quick test for a faulty EGR valve causing this erratic engine condition would be to disable it and if the engine suddenly regains its lost power the EGR valve is the problem. Cleaning or replacing it cures the symptoms. On the other hand a closed EGR valve staying closed allows the engine to run better but the higher combustion temperatures (that the EGR valve prevents by allowing exhaust gas to mix with the fresh air/fuel mixture) generates more NOx, the reason for yours not passing emissions. There's a remote possibility of the catalytic converter going bad but not likely unless you've been dumping exotic flammables in a quest to boost fuel economy or hope to make more hp. Remove the EGR valve and have a look-see for a cleaning, paying attention to the moving shaft that allows smooth movement opening/closing. An electric EGR valve may be blown also so having it tested at an auto store may help determine this.


BTW, where's Chad?Edited by: ducky

Thanks Ducky for responding.

I had an emissions diagnostic done and you are right, the egr valve is
not operating correctly.

I have a 98 SL! with an electronic EGR valve.

I've tried cleaning it, but no dice.

I think it's time for a new one.

Can anyone suggest where I can buy a new one from an online retailer, perferably an American one. I am in Canada by the way.

Well, there's rockauto.com, saturnparts.net, and some used car sites online advertising on another Saturn forum (if you Google Saturn fans sites). The prices are high as the electronic EGR valve now contains afeedback position sensor.

Thanks

Has anyone from Canada ever ordered from the states?