Taco suddenly quiet

Hey guys, kind of a weird situation I'm in.

Had the local shop check up on some stuff on my 02 auto v6 4x4, they didn't find anything except recommend the fan clutch replaced, they already had my truck so I just had them do it.

Get my truck back, and it's suddenly quiet and feels like the power is lagging. I got a cat code, and figured the front cat failed and ended up getting both cats replaced (she has 250k on her).

Truck then feels a little better, but still quiet and not accelerating the way it did.

My thought is maybe there's something in my muffler, but if a squirrel ran up there I figure I'd smell it by now. Or maybe when the shop changed the fan clutch it changed my timing a little? But idk if that's possible.

I appreciate the help.

 

Many years ago, I had the inside of a muffler collapse. It obstructed the exhaust to the point where it would barely run above 1,000 RPM. Not saying this is your problem, but I've seen it before. Recently I had a car with clogged cats. I removed the O2 sensors so I could open a hole in the exhaust pipe for the engine to breathe. This may not be possible depending on the condition of the O2 sensor mounting bolts and nuts. Where I used that method to diagnose a clogged exhaust had recently installed new O2 sensors that were easy to remove.

 

I've always had this thought as a way to see if a cat or exhaust was obstructed but haven't needed to do it yet. Was it easy to tell in the way it ran after you pulled those sensors and left those open?

 

Put a shop vac on the tailpipe, if the exhaust is plugged vac will whine like a banshee instantly. You will be able to tell, worse case remove egr tube and try it

 

Thanks for the input. I'll try taking out the sensor and the vacuum thing. Will update with results.

 

Oh yea.. Huge difference once I opened a hole in the exhaust so the engine could breathe. It was loud as all get out. But then it ran like normal. It gave me a way to open the exhaust pipe with the least amount of effort or risk associated with removing/loosening the pipe.

Now if the O2 sensor bolts and nuts are all rusted over, that's a whole different problem.

 

Gotcha gotcha, I agree. Just didn't know if the holes would be big enough, I've started up engines with the down pipe disconnected. Good to know pulling the sensors might give a good idea as well