JCleary

My truck used to run like a scalded dog. It would want to spin up the rear tires all the time, especially with the TC turned off. Even with Nitto Terra 305/60-18's and later 33x12.50-18 Toyo MT's. Now with puny 285/65-18 Toyo AT's the thing won't even light the tires.

I'm not sure why, but with the new charge air cooler, left catalytic converter and programming my truck is just not fast any more. Sure, it pulls alright, but not with the ferocity that it used to.

I wish the dang check engine light never came on. I liked my truck a lot more before, even with the weird engine performance in the rain.

Has anyone else had this same thing happen?

1fastecoboost

exact same thing turned out tune wasnt up to par with wat i had and my plugs where not gaped tp spec 0.30-0.32

JCleary

My truck is 100% stock, other than a leveling kit and tires.

Spark plug gap on a stock truck makes that much difference? What a PITA, but I guess I can check this weekend...

superccs

Yeah check out the EB sparkplug gap thread its informative...

1fastecoboost

very much so; alot of people are having the same issue

craigd853

They did the same thing to my 2011. I noticed the same thing as you did. I took it back and talked to the mechanice and when the computer is reflashed for the TSB it is actually detuning the engine somewhat. My Blow Off Valves kept going off so I explained that I didn't want to hear this everytime I left my foot off the gas so they detuned it even more. Truck still has plenty of get up and go but like you said, it was faster before all of this. I eneded up putting a SuperChips tune on it and now have my horsepower back.

maplelakeduckslayer

Put new plugs in mine gapped to. 032 and truck had tons of power back for 4 days...then it dropped off again. This was 2 weeks ago. Gonna switch plugs again and see if I have the same results. I have a feeling the only way to permanently fix it is to potentially lose my warranty and go aftermarket tune. Have a feeling computer makes adjustments to drop power when it senses something is off.

CoreyMS

Did you disconnect the battery while changing plugs?

Bc if you did, it would be more plausable than the plugs being the difference. Battery equals keep all memory cleared, then it learned and slowed down.

maplelakeduckslayer

Actually I didn't disconnect anything, which leads me to believe for some reason the computer is making adjustments. Last week after it began running crappy again I disconnected the battery for 4 hrs with no change in driveability. So I figure if I change the plugs again and get the same results...at least I can say it runs good for a while with new plugs.

It did the same thing after the CAC replacement but figured that was surely relearning. But after it happening after the plug switch with no relearning I'm not sure what to make of it.

JCleary

Reminds me of the BS with the early 6.0 liter Powerstrokes. I had three at my shop. With every warranty repair they lost power. Man, did they haul **** when new! Just like my Eco. Sure wish i had the 5.0. Damn. Wish I never checked the Ecoboost option box...