Loss of acceleration and power. Motor sounds forced

I have a 99 Toyota Tacoma prerunner 4 cylinder 2.7L. The symptoms that I have on my truck are lack of acceleration, loss of power, motor sounds forced like if it's sucking up air, can't go passed 2500 to 3500rpms, bad MPG, seems like it has very low gear not a smooth ride at all. As I was driving 3 hours away from home I came across a steep hill, and my truck sounded worse and I couldn't go pass 40 mph uphill and I wasn't forcing it at all. Also once I got home I noticed that my transmission was leaking a little bit of oil. I'm guessing my transmission was overheating. I have recently done a fresh tune up on engine and transmission, I have a rebuilt transmission, and I have replaced brand new parts such as radiator, fan clutch, water temp sensor, thermostat, 02 sensor, transmission temperature sensor, battery, alternator, starter, manifold, manifold gaskets. What can the issue be? Can it be my catalytic converter? I Also have no check engine light at all. Can anyone relate to this issue and help a brother out please? I would want my truck running cherries as when I first got it.

 

It's not unheard of for a rebuilt tranny to have been done poorly

 

Will it go past 2500 in neutral. CEL?

 

The gears shift smoothly from the transmission, its just the hard acceleration and lack of power is what I'm trying to figure out the issue. And no it won't it slows down.

 

Sounds like a plugged cat. Does engine sound like it is struggling to run even while parked and under throttle?

 

It could very well be a plugged catalytic converter.

 

Yes it sure does, while parked and trying to Rev it, sounds like it's sucking up to much air. I have no check engine for the catalyst converter. Even though catalyst plugged a check engine won't pop up? Is there anyway I can unclog the catalyst converter? Any chemicals to unclog it?

 

There is no exhaust back pressure sensor on a 1st Gen Tacoma like on a commercial diesel truck.

 

Will it work to clean out catalyst with lacquer thinner leave it in a bucket over night and see results the next day?

 

Sounds like wishful thinking. Btw, there is a post catalyst O2 sensor that monitors catalyst function. Will tell you if catalyst is below threshold (P0420), but not if it’s “plugged.”

 

a muffler shop can check for a plugged cat in a few minutes. There isnt any known way to clean a catalytic convertor, they have to be replaced. If you are in a smog state you are going to have to replace it and aftermarket parts are expensive. If you do not live in a smog state they can knock the insides out and you can run without a cat but the CEL will illuminate after a short drive. Underdog racing used to sell a rear O2 eliminator that would fool the PCM but that has been discontinued as far as I know.

 

Thank you very much ill give it a try.

 

Check the air intake hose for a crack and the filter for clogging.

 

I double checked the intake hose good and filter clean. I have a k and n Intake installed.

 

Can you post a video of the sound? Sucking in to much air? Hood up and throttle it by hand, listen and look? Check your fan clutch?

 

To check for plugged cat , you need a vacuum gage connected to the intake manifold below the throttle body .
Once the vacuum gauge is connected and the engine is running , snap the throttle wide open for 1 second .
You will notice that vacuum drops immediately . You are looking to see how long it takes for the vacuum to return to 15 to 17 bar .
Obviously if the needle on the vacuum gauge slowly returns to 15 to 17 , your cat is plugged .
If the needle on the vacuum gauge returns very quickly , your cat is fine

A vacuum gauge is a cheap tool that can really tell you a lot about your engine if you use it correctly

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