There's knocking loudly and muffler sounds loud as I'm driving and the catalytic converter sounds like something is loose inside of it.
Aug 28, 2023 at 1:06 AM
Repair Safety Notice:
This information is for general instructional purposes only. Vehicle repair can be dangerous.
Verify all information, follow manufacturer service procedures, use proper tools and safety equipment,
and consult a qualified repair shop when needed.
Advertisement
STRAILER
AUTOMOTIVE REPAIR CONTRIBUTOR
54,176 POSTS
2020 GMC JIMMY? This happens when the catalytic converter is hot and then water gets slashed in it which breaks apart the honeycomb inside the converter. This means it will need to be replaced, here is the new catalytic converter on amazon for $135.00 I believe.