JUst picked a 2002 z28 for my project car(weekend warrior mechanic)...check engine keeps coming on and off. Stays on for like 2-3 drives then shuts and then repeats. Took it to Autozone and they reset and checked with computer...says it's running too lean. Is this a gas cap problem(seems like it's too loose) or do I need to use Premium fuel.......any suggestions are appreciated. Thanks.

 

could be o2 sensor,dirty fuel filter..what do the plugs look like?

 

Thanks for the suggestions..i'll check those.... and report back...MD

 

When you get it scanned, get the EXACT numerical code, in the format P####. That way we can tell you what the most likely problem is, using the GM code lists specifically for your car. The scanners often provide very generic code descriptions, that really don't tell you everything you need to know.

A gas cap problem will not make it run lean.

If you want to get the full performance your engine is capable of, you have to use premium fuel, per the requirements stated in your Owner's Manual. Using low octane "regular" fuel won't make it run lean, and won't harm the engine, but usually it causes spark knock, and the knock sensor/PCM pulls ignition timing to prevent engine damage. When you pull timing, you reduce power output.