2013 ford f150 ecoboost torque converter issues
 

I'm just a girl, don't really know much but need confirmation I'm being told right...
My baby is a 2013 FX2 ecoboost 160,000 miles. At highway speed 70-80 if I go to accelerate (too hard too quickly I guess) my truck begins to shudder, loses power & the yellow check engine light flashes for about a minute then all goes back to normal. Sometimes when the flashing light stops it will stay off other times it will stay on & that's annoying because then my remote start wont work till my husbands friend comes over with some computer thing & clears the code.
THEN other times when I'm just rolling slowly through a parking lot my truck will make the violent hard jerk 1 time then its fine. it literally feels like I just got rear-ended.
is this in-fact my torque converter yall think or...???
One sec., small history note: When this happened before FORD Dealer said it was a misfire of cylinder 3 & they "fixed it".
Um, no, NOT FIXED.
Ok any advise welcomed.
Thanks,

It certainly isn't the torque converter. The ONLY way the check engine light can flash is for an engine misfire. You have a misfire problem.

You need to service the plugs and coils, also consider drilling a hole in the intercooler to drain the moisture. The 6r80 is a good transmission, when was it last serviced?

Has your truck ever had the misfire TSB done? It involves the shield on the intercooler. Some of us drill a small drain hole in the intercooler, especially in high humidity environments. It helps the condensation drain.

On the ecoboost, you have to replace the boots and the plugs at the same time of the misfire problem could persist intermittently.

The hole that was referred to in the intercooler is a 1/16th size hole on the drivers side lower corner of the intercooler. The hole isn't large enough to lose any boost but just large enough to force out all moisture that otherwise may be getting drawn into the intake system. I did it about 40,000 miles ago and nary an issue.

Lastly, as asked before, when was the transmission serviced last? At 160K, you're due for a flush as per your owners guide.

Definitely need to do the coil boots at the same time as the plugs. The drain hole is a good idea too. You need to get it scanned again to see which cylinder is now causing the misfire and put another plug in that one. I normally replace the coil as well for good measure. What happens with worn plugs is the spark jumps between the plug and boot instead of the electrode. When that happens a small amount of rubber is vaporized and leaves a carbon track in the boot and on the plug. Now the spark has 2 routes to take instead of 1. When you just replace the plugs the track is still in the boot so the next time the spark jumps outside it makes a track on the new plug. Then if you just replace the boots or the coil thinking the plug is new so it has to be good the track remains on the plug. Have to do them as a set.

Replacing the torque converter will just waste a lot of money. There is nothing wrong with the torque converter.

The problem is in the engine, not the transmission or torque converter. Listen to what the others are telling you about the spark plugs/boots/coils. That's where the problem lies.

99% of the time its the engine causing the shuddering and vibration. The torque converter almost never gives problems.

Also worth mentioning but when it misfires and the light is flashing you are causing damage to the catalytic converters and it's not cheap to replace them.

Cats may be fine. Solve the misfire with above advice and go from there.