The Cat on back one of my 2001 5.3 has failed. Apparently the internal honeycomb has broken apart. It rattles. Sounds exactly like a loose baffle in a muffler. I’m certain that the sound is coming from the cat.

Upon pulling code for a SES light I got a code P1415 - secondary air. Upon doing research I figure it’s a bad check valve.

My question is this: would a bad check valve have a negative affect on the CAT? I want to fix the underlying problem before replacing the CAT.

Thanks for any and help!!

 

it won't damage the cat but may damage the air pump or whatever system your truck uses to pump air to the cat. it will reduce the oxidation efficiency of the cat. the check valve purpose is to keep exhaust gas from flowing back to the engine/air pump. the air should flow to the cat for redox reactions. if it flows to the air pump...damage will occur to the pump.

if you hammer fist the cat and it rattles the element is loose and could move and cause an exhaust restriction