08 GT auto. 147,000 miles. Only CAI and "93 Octane" Diablo Predator tune. When started from cold, the idle surges up and down for 15 or so seconds, then settles in. Throttle is a little erratic when pulling out, but then that settles in. Second set of Motorcraft plugs have 50,000 miles. Gas filter about 30,000.

 

When was the last time the TB was cleaned and fuel filter replaced?

 

TB has been cleaned twice since new and gasket changed once. Fuel filter has 30,000 miles, but doubt its that. Just disconnected the neg terminal for a half hr and the start up idle was steady. Lets see for how long

 

If all else fails, maybe replace the front O2's. Only use Motorcraft if you do, Rock Auto has decent prices.

 

Definitely clean the TB.