Power Loss & Vibration

Hello,

I have a 2005 2wd 4cyl auto reg cab Tacoma with 65K on the engine. About 2 months ago I would periodically lose power @ 20mph-50mph with slight vibrations occuring in those speeds. Recently it has gotten worse with stronger vibration, and it happens between 20mph-65mph.

I changed the air filter.
Changed the plugs, and checked for spark. There is spark
Cleaned the throttle body.
checked all hoses.

I noticed a slight vaccum coming from the exhaust. The exhaust needed to be forced out w/the gas pedal down, otherwise I could barely feel it.

I'm thinking either:
clogged catalytic converter
egr valve

Thanks in advance for any suggestions!

 

Welcome to TW. Run some SeaFoam through your engine. Maybe that can help.

 

Try this I think it will help you determine if the problem lies in the engine or in the cats

 

Is it just me or does this sound wrong to everyone else too? I understand the exhaust to be a one-way pipeline from cyl port to tailpipe and there should be no way no how there is ever a vacuum in the exhaust. ??? /????

 

The exhaust is not sucking back up into the engine. When i put my hand over the pipe I can barely feel it coming out. I put my hand over the pipes of 2 other vehicles and there was a big difference between them and the tacoma.

 

Loss of power is a symptom of a blocked or obstructed exhaust. Your engine can't breathe if it can't exhale.
If you can, pull the pre-cat o2 sensor and check pressure.

 

02 sensor