Hello I have a 1991 single cab pickup 4x4, 5 speed with 22re, all stock. My truck has been running very rough loss of power and pickup, so I did a full tune up cap, rotor, plugs, wires, airfilter, and fuel filter. Now the truck is driving better but it still hesitates all gears feel like there just lacking power, and when i finally get to 5th and go 50 mph no matter how far i push the gas pedal it just slowly slows down, and my gas millage has been terrible feel like i have my old v8 again. There is just no pick up or power even if i rev it it takes forever i can barely get to 50mph and 4th gear barely holds it. So what you guys think is goin on here?

 

Clogged cat??

 

A clogged cat would cause that also do you have an air leak in the intake system?

 

I dont think i have an air leak in the intake, but the clogged cat thing sounds like a very high possibility, didn't even think of that.

 

Welp took the cat off and not too much changed, but my throttle cable was very loose tightened it up a bit and the response is a little better, but now im leaning more towards a vaccume leak cause all my lines are old brittle and some look split so I guess the next step it so replace those. Any other ideas??

 

Just spray a mist of water over the engine to check for a leak. If you see it get sucked in somewhere then you know you have a leak. Might I suggest a good seafoam cleaning?

 

Did you check ignition timing? (You need a timing light, $20)

You can use an unlit propane torch to look for vacuum leaks; the idle will increase as the propane enriches the mixture when sucked in.