aveo engine and hold light came on

hello.
I have my aveo 2008 engine and hold light come on the engine barely hold it self on idle but when I accelerate the engine works well the car seemed to be stuck on a high gear I got it scanned with my own obd2 scanner the fault was p0300 random misfire. when I deleted the codes the car started to go better but the engine rough idle stayed with no trouble codes.
got my spark plugs spark wires and coil replaced the car got a little better but afew miles after the car had the engine light and hold light on once again with rough idle and gear stuck on high gear. what could be the problem?

I'm having similar issues. About to order coil pack and see how engine responds...

You haven't washed the engine bay bay any chance have you? I had a very similar problem after washing my Aveo's engine and it was because the spark plug wires had gotten wet.

Have you tried the water spray test? Use the search function to know more about this method.