Clogged cat ?

Well it wasnt a clogged muffler. The crap inside of it was just what was left of the rotted tubes. Took it out cut it open and it was hallow.Thats why it sounded funny. Exhaust bouncing everywere. The cat looked fine aswell.

To make things worse the replacement muffler was wrong. Pipes on the muffler were the same size as the exhaust pipes so I couldnt slip the pipes inside it. Now I have a rigged on muffler tlll I have the time and money to fix it. may aswell just replace the entire system and be done with it.

How ever that still leaves me with a crappy running truck. I have no idea what it could be. It hasnt tripped the engine light so looking for codes wont do me any good.

It runs like crap at part throttle and cleans up at around 2500rpm. As sson as it shifts and the rpms come down it runs like crap all over again.