Review Of 2004 Chevy Classic Check Engine Light References. Here are 10 possible reasons why don’t panic if you see it — it doesn’t necessarily mean you’ll need to give your next paycheck to the nearest mechanic. A loose gasoline tank filler cap will illuminate the cel.
However, it can also signal issues with the oxygen sensor, catalytic converter, air flow sensor, ignition coil, or spark plugs. The reason why the check engine light might come on in the 2004chevrolet silverado 1500 could be from a loose gas cap, bad o2 sensor, problem with the catalytic converter or a bad spark plug. It ran much better but engine light came back on.
