Many different things you need to take it in to a auto zone parts store and they will put a scanner on it for free and give you the codes it has stored and how to fix it.
In my experience with my Chevy it was a ground wire
with me it was the o2 censer
You need to check all of the mounts. Get a manual to show you where they are.
To determine the cause of a 'service' light activating, you need to have someone with the appropriate equipment connect to the car's computer to read the code for a particular problem.
TRY CHECKING TO SEE IF YOU HAVE A HIGH BEAM HEADLIGHT OUT. tHIS WILL CAUSE THE PROBLEM YOU HAVE.
The vacuum lines for a 2000 Cavalier are located all over the engine bay and under the dash. A break in any line can cause rough running.
There are pages and pages of things that can cause a check engine light. You need to have it checked with a scantool. Then the code can be diagnosed and repaired.
Low fuel pressure
What would cause the engine not to restart when hot Chevy Trailblazer 2007?
Engine overheating. Check the radiator for leaks in the hose pipe or radiator, otherwise the water pump is faulty and will need replacing
There are pages and pages of things that can cause a check engine light. You need to have it checked with a scantool. Then the code can be diagnosed and repaired.
have you checked your fuses?