For a few days now my car has been shaking when the car is idle. i can also see the RPM's fluctuating a bit while in idle. what do you guys think the problem?

could it be because of wiring? i just installed glow gauges on the car.

 

Misfire or vacuum leak. Start by replacing plugs and wires and testing coils.

Any codes?

 

Ditto, check the vacuum system, PCV valve.

Also, if you haven't done it, use a fuel system cleaner. And it may be worth it to do a run through with Sea Foam.

 

mmmmmmmmm, does the vacuum system actually sound like a regular house vacuum if there is a leak? because i've been under the hood a few times while the engine was running and heard something that sounded like that.

how do i check if there is a leak?
is it possible to fix by myself?