While at idle, my rpms will jump up and down, similar to a miss. Every few seconds there is a pop/backfire sound from the exhaust. The car lacks power at low rpms, but seems to be fine at higher rpms (no miss or backfire, power seems ok)

I know you guys are going to tell me its the opti, or plugs and wires, or the egr, ect.

I have had problems with plugs/wires/coil before, they never created these symtoms for me, so i dont think they are at fault.

I Think the problem lies with either the opti or the egr, there must be a way to tell which is at fault, without replaceing either one.

I have also been having a problem with the circut the egr is connected to. The "fan fuse" has been blowing randomly, the egr is on that circut. Could a problem with the egr also be overlaoding the system from time to time, causeing the fuse to blow? (the fuse will go weeks without blowing, or 10 min.)

thanks for any input

 

ttt

 

try connecting a vacuum guage to the engine and check the vacuum readings. it should be stedy and at least 18 inches of vacuum. the neddle also should not jump around when idling.
even disconnecting a spark plug wire will not make a the engine vacuum reading jump only mechanical problem will such as burnt valves, broken valve spring ect.

 

Sounds like an EGR valve problem or and intake elbow leak. Check the connections after the MAF sensor and to the throttle body and see if there are any leaks. The fuse prob sounds like some wire is showing through the insulation and grounding it out once in a while....Check the length of the wires from the fuse and see if there is any bare wire showing.

Matt