Questions and Answers

Saturn SC Fails Emissions Test Q. I am having a problem smogging my 1992 Saturn SC DOHC. To date I have replaced all of the following parts: O2 sensor EGR Solenoid EGR valve Timing chain Spark Plugs Spark Plug Wires Catalytic Converter

My car still fails with High HC's, about 159 at cruise. It idles relatively smooth most times, except once in a while it feels like its missing. I noticed last night while sitting in the car that the lights seem to dim when the car misses. Is this normal for the car or do I have a serious problem with the electrical system that could cause the high hydrocarbon results? I have also noticed that the tailpipe is covered with oily soot inside. I've never noticed this with any other cars I've had. What's up with my car???

Thanks for your help!

A. You need to get the fuel pressure specs and put a gauge on it. Too high of fuel pressure will make it run rich and cause high H/C's. Also, replacing all those parts doesn't mean they are all working properly. A scanner would help here so you can see what the PCM is doing and read the data from all sensors.