Hesitation in passing gear.

I recently had my truck serviced for a little hesitation in passing gear and while pulling a travel trailer. Mechanic updated software and cleaned the throttle body. I replaced the spark plugs a while back and no luck. Any suggestions?

 

need more info, what engine in the truck? Mileage? How long has it been happening and all the time or only towing? How long have you had the truck, and any other running issues? Has the truck been well maintained?

Here is more on the software tsb https://www.tundras.com/threads/2012-to-2014-ecm-software-update.1205/page-2

 

The engine is a 5.7 225,000 miles and oil changed regularly. Runs great just when it is shifting into overdrive.. I have owned the truck since 2015. It has been doing this for about 3 months. I have had an instance recently that when the truck is idling for about 10 minutes it starts to run real rough. I have run seafoam through her several times and doesn't seem to help. If I step on it to pass it won't hesitate, its more of a slow pass or when I have cruise control and going over an overpass and it kicks down to keep speed.

 

throttle body, MAF cleaning. change plugs if it has been close or over 50k miles since last change. I would do a drain and fill on the trans as well and hook up a reader to see if the truck is throwing any codes. With those miles, coil packs could have issues or hairline cracks which would cause missfire and rough running at times.

The trucks do act funky sometimes when in cruise and accelerating, noted here on the forums before, folks considered it more normal vs a problem.

 

Yesterday I had to wait in a line and it started running real rough. The check engine light was flashing. It stayed constant for a bit and then the 4 lo light is flashing and the traction off light is on.

 

then you have codes that you need to check. get a code reader or go to the auto parts stores that will read the codes for you and see whats up.