I have an 02 E350 5.4L that continues to melt the left side converter up. The engine seems to be running too lean on the left side. I took the Y-pipe off and found chunks of converter in front of the main converter (total clogged). Does anyone know what the f##k is going on? This is the third converter. The right side converter is still good.

 

Have you checked for any valve problems or do you have any other problems?

 

The engine runs great when main converter is not clogged.