2005 exp low idle Tap and Stall in reverse
Hello all, i can not figure out what is wrong to my expedition. here is the scoop
2005 exped limited 5.4Liter 87K miles
It started a year ago when the check engine light came on when i was at high rpms and started to blink. ever since that i have lost power and acceleration. and the check engine light would come and go. i had some engine coils replace and that fixed the problem in the short term
recently it started to happen again but now
I get a tap in my engine at low idle and when i put it in reverse and just tap the gas it stalls. It does not stall in drive but at low idle or if i tap the gas it will tap. Ford has replaced engine coils, solenoids and part of my cat. The car is in mint condition and the service manager said to me he cant figure it out and i should just trade it in. I have it almost paid off so i would rather not.
I recently took it to a garage and they were the ones to replace some engine solenoids and upgrade some software. It has recently gotten much better but it still stalls in reverse and the power is not fully restored. i have been putting high octane fuel and that has made it much better. I asked the mechanic if it could be a piston and he said that the engine is in pristine condition. I have not had a tune up on the car yet. could spark plugs be the cause of this?
any help would be appreciated.