I had the oil changed and the fuel system cleaner done at the dealer ( 52,000 3.5 eco). Later that day the truck developed a miss above half throttle. I did have a 93 performance tun in it so I put the 87 performance in and it moved it up to 3/4 throttle. Now I have the stock tune in it and can just make it out at WOT. My guess is an injector is somehow clogged. Lets hear what your guesses are before I take up to find out.

P.S. I have been running only premium name brand fuel.

 

Reminds me of a girlfriend many moons ago, who insisted I address her as "Miss Fire". I soon learned why.

 

I thought this was about miss doubtfire.

Doesn't seem like a sticky/clogged injector would be dependent on a tune.

Not sure if the plugs could have gotten somewhat fouled during the process -if maybe truck idled for a long time during the process.

 

I haven't pulled the plugs yet. Thanks for reminding me.

 

Fuel system cleaner? I bet this did it.

 

Exactly. "had the fuel system cleaner done", why? Not a service recommend or required in the manual.

 

yep.

This is a sham. Especially on direct injected motors (even with PI).

 

Hey, if you really miss fire, let your truck burn, and then get a new one, and NEVER do that crap to it again . J/K. Good luck.

 

The dealer did it saying it was recommended. I haven't done that in 15 or 20 years. Betcha I won't again.

 

Dealers are lying (words i cant use here), they just want your money.