My 90,000 mile 4x4 2002 1500 suburban has developped the following symptoms:
- sounds louder on acceleration (sounds deeper, louder), but i can't seem to see/hear any exhaust leaks
- no acceleration, feels like it's running on 6 cylinders or less
- when trying to accelerate, it pings, sounds like detonation
- OBDcode 0300, "Random misfires"

Any idea?


Thanks in advance

 

In case anybody runs into this in the future, it was a clogged catalytic converter. $500 and 5 hours later, it's changed and running well. Now, I may need to change the O2 sensors so it doesn't happen again. Any body have any idea how to test O2 sensors??

 

Welcome to the forum and thanks for taking the time to follow up with very helpful information!

 

Welcome to the forum. Thanks for the update.

Some of the auto parts stores sell sensor testers. Not sure O2 is one of the sensors they can check tho.