Recently I installed a 4 inch down with dpf delete, yesterday when starting off from stop i heard a different noise. I never heard it for the fiirst week after install. Its not constant but brief when first accelerating, I thought it was an exhaust leak, but everything is tight, can't hear it if in park and reving the engine. Anyone familiar, or any ideas ??? The best way to describe it would be belt slippage, but not a screach. Thanks for any info....

 

Hmmm not sure. Sure its not just the sounds of the new exhaust. Is it coming from the engine compartment or where?

 

Exhaust Leak?