if the vehicle shifts and drives fine. the most probable cause for this is a high idle. most vehicles idle at around 650 to 700 rpms. when warmed up, check or clean the idle air control if idle is high. good-day !
Depends on where the noise is whats making the noise. Can you be more descriptive of where and what?
high idle problem on a 1997 sc1 when car is in gear
No, that has nothing to do with idle speed.
you have a bad alternater or belt
When you can not figure out why your car makes a strange noise, you take it to a mechanic.
Yes if it is stuck open.
I would get it checked out by a profesional because that one is a hard one to deal with if it doesnt get done right
chech catalyc converter or muffer. check also o2 sensor or egr valve.
It's usually a vacuum leak.
Adjust your idle.
Have you checked your Exhaust Muffler and pipes ? Probably the fuel pump