I recently had to cut out my cat converter. It was already hollowed out but it rusted apart and needed cut off. So I straight piped it back to the stock muffler and now I lost alot of power. Could that be due to not enough back pressure in motor.
If so what can I weld in to increase back pressure. The stock muffler is pretty old and probably wore out inside would a new muffler help?
Im scared to drive it cause I dont want to hurt the motor.

 

I would weld in a catalytic converter. There are some aftermarket ones that should work.

 

Okay I welded a new converter in and its running better but not how it was. All there was before was a hollowed out converter and stock muffler. I dont know if the something came loose in the muffler when it was straight piped. But its still rattleing and raspy Inside the muffler even with the new converter. Its running better but still kinda choked up I lost alot of power I feel. any help?

 

Check vacuum for indication of restriction. See link for diagnostic indications:

BAT Auto Technical-Professional mechanics giving advice-An Educational Site w/ OBD2 Trouble Codes and Technical info & Tool Store.

good luck

 

Okay I have a vaccume gauge where do I connect it to the car to get these readings. Its a very useful chart but I couldnt see instructions on where to check for these problems at

 

Any place where you can tee into a vacuum line. You need a tee a short piece of vacuum line to attach. It must be a continuous vacuum line directly attached to intake manifold.

good luck