I have a 2002 Tacoma Prerunner it has a Little over 400,000 miles. It gets i think 11 miles to the gallon and if accelerates slower than normal unless you want to floor it every time you come from a complete stop. and if your going around 45mph and you floor it it will back fire but it doesnt do it every time.In the morning if its really cold it has a hard time accelerating and the only way it can accelerate is to put the pedal to the floor and it accelerates really slowly. I know the fuel pressure is good, has new spark plug wires, the catalytic converters are good and has new coils.

 

Which engine do you have - 3.4L or 2.7L? What, if any, maintenance and/or troubleshooting have you done recently to help figure it out? Showing any check light/engine codes?

First things I'd do is check for codes, fluid levels (esp. auto trans), check plugs/wires, check for dirty throttle body/clean check MAF/clean it, Lastly I'd check the TPS (throttle position sensor).

Hopefully this helps. Good luck and welcome to YT!

 

Its a 3.4, the Transmission fluid hasnt been change. Ill see what codes it has soon and Ill post them on here. Another thing I'll add that it does that when you accelerate by pushing the throttle halfway the RPMs will rise and to me it seems like the speed you're doing doesnt go with RPMs.