Had the heads done reccently, new plugs, new wires, new cap, new rotor, Have the Downey headers, have had all sorts of exhaust leak problems... reccently the mileage has crashed, and there is no power... other than that it appears to be running ok. I have noticed, that the temp gauge will fluctuate, but that started prior to the crappy mileage.

 

hmm... maybe the temp sensor, or iac valve? just guessing.

 

Cheap gas?
Air filter?
Gunk buildup in the intake/injectors?
Vaccum leak?

When I first saw the title...I was gonna say thats normal...but I'm sure there is something simple.