My yukon won't go past 50 mph with 6 rpms

What is your question?

Loud sound coming from the muffler rpm goes to 6 and won't go past 50 mph I recently changed the maf sensor catalytic converter and nothing please help

What makes this problem better or worse?

When I accelerate it forces the motor

How long has your 2004 GMC Yukon had this problem?

2months