I've had the engine stumble from having moist air come through but never got the check engine light. Till yesterday.

Took to dealer. Code was for the catalytic converter. (misfires allowed fuel to get in the cat which roasts them) I've got the original air charge cooler from 2011. They are going to put the big plastic air block on the lower part of the air charge cooler and put a new cat on tomorrow. I imagine the engine power will be dumbed down with the latest ECM update too.

My mileage has been terrible lately and truck has felt like it didn't have power.

Tell me why I have a turbo charged engine if they are dumbing it down??

I'm so happy, not!

I am going to have them check the plugs, possibly replace all of them while I'm there.

My truck has 40,000 miles on it. EcoBoost, the gift that keeps on giving.

If you've never had an issue with your 2011-2012 EcoBoost, you will.

 

All they will do is install new cats and install the newer air deflector on the CAC. Also I was told by my dealer last year that running ethanol gas was causing the misfire issues and causing the cats to be burnt.
Another thing you can do is Re-gap you're plugs to .030 this will maker her run smoother and all but eliminate the stumbling.

 

There is an excellent thread in the 2009+ F150 Forum from a Ford
tech about the sparkplugs. Ford says they're good for 100,000 miles,
but he had pictures of problem plugs with half that mileage.

It left me with the idea that these plugs need to be changed by 50,000 miles. Here's the link

https://www.ford-trucks.com/forums/1...formation.html

 

I did see that video. I had the techs change out my plugs at my expense for peace-of-mind. My truck had 40k miles on it at the time. None of my plugs showed signs of carbon tracking.

 

Carbon build up isn't the issue - they are all gapped different from the factory. If ya re- gap them to .030 the EB will run a lot better and more smooth