Hello I am new to the site and need some help with a issue I am having with my truck. First I have a 1999 f150 xl 4.2 v6 5 speed. It has 68100 miles and was never abused. I purchased this truck from my father who used it for leisure rides and really never exceeded 60 mph. The other day I stopped for gas and when I started it up the service engine light came on. Truck ran fine to where I was going but when I was returning home there was a stutter while accelerating. I took it to my friends garage and there was a dozen errors like o2 sensor bank 1 gas cap IMRC etc. He decided to reset them and said drive it around and see if it come back. It did and had same errors. I did some investigation on this site and checked for vac leaks IMRC linkage bushings etc. Found nothing. The fuel filter, spark plugs and wires were all changed 500 miles ago when I did the oil change. The problem isn't constant for example I started it up let it warm up for 5 minute or so and took for ride. It started to sputter through all gears. Now today I let it warm up long enough for the idle to return to normal and same issue. Stopped at store started up took for long ride and no stutter. From what I have read if the IMRC was bad you would see it when the rpms get near 3000. One thing it did notice is when I was driving down high way I sped up to 75 and could hear what sounded like a ticking like when a wire is bad, now is that the IMRC buttery fly's making noise since I do not have a tach to see where I am? Also the fuel pump was replaced around 50k. I tried injector cleaner, dry gas higher fuel grade and sea foam (questionable if it really works). So if anyone can share some advice I would greatly appreciate it. thanks Bob

 

I suggest cleaning the the inside of the throttle body where the air intake attaches AND spraying the maff sensor really well especially the intake and you might want to look into your 02sensors

 

Injectors