my engine light turns on everytime i drive it up to 4000rpm. When i shut off the engine, then start it up again the engine light isn't on. It only comes on after i drive it for a while. Does anybody know what the hell it is or how i can find out what it is? will an obd 1 scanner help me and which one should i use?

 

ouch that totally sucks man.. does it come on exactly at 4000 or around there..