I bought my 2004 Chevy cavalier about a month ago and it has all around been running just fine.
Yesterday, when I turned my car on the gas needle went way past the full marking, when before it was quite a bit below. When the car was turned off it went down to 1/4 of a tank. This problem corrected itself and went back to normal.
Today, I shut off my car and a few minutes later turned it on; the check engine light turned on!!!
I'm completely confused, as the car sounds like its running like normal..
Help, anybody? =(

 

Take it to AutoZone and have them check the codes.

 

There is no autozone where I live.. =(

 

Buy you a OBD II scanner, it'll come in handy for future use also.

 

OBD interface for laptop will cost around $100, methinks. My wife has engine light on every now and then, she already knows how to fix it ... she didn't put the gas cap on properly.

 

I had the same problem with my truck last year. GM had a problem with the soldering on the backs of the gauge clusters cracking and breaking the circuit. This problem is easily fixable by the dealer or someone who has the knowledge, I dont know where you live but the contact I have did mine and was awesome. He came to my job and did it in the parking lot and it took him about 40 minutes and it cost $150. Plus he re-did all the soldering and replaced the lights that had gone out too. If you go to a dealer they will quote you around $600, but my guy is in Texas

 

My whole cluster went nuts. Gauges looked like windshield wipers, lights blinking. Put a 6 inch ground wire from the block to the chassis using the top motor mount bolts. All is good.

 

Thank you very much for your replies!
I took my car in to a shop and got the code read, it said that my car had an emission leak, and that could either be from the fuel line or the gas cap wasn't on tight enough.
The light hasn't come back on, but my gas needle's still screwing up.
Yikes.
Btw I live in Canada!

 

My money is on gas cap. How much did you pay for diagnostics? Compare it to the cost of an OBD interface from eBay.

 

I found a little shop that did it for free, all the others wanted to charge 60 and up.