Originally Posted by Jeremy5848

I have not heard of clogging problems with a trap catalyst on an OM617 but it could happen if a car were driven extensively at low speeds, much idling in traffic, etc., and never given the opportunity to burn off the collected soot. There is a factory procedure for measuring the back pressure using a pressure gauge connected to a port at the rear end of the exhaust manifold, just before the trap cat. I don't remember the spec -- the book isn't in front of me -- but an excessive back pressure indicates a clogged trap.