Forgot to mention, that it is possible that your problems are not in the CAT as someone has already posted. I changed my CAT because it was completely clogged up and I had no vaccum at idle. Consequently, my RPMs would not go above 2000, a total loss of power is what I had. Also the mileage that this happened was 350K, so these MB cats are quite well built, rule out other mixture adjustment possibilities before changing the CAT.

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Saumil S. Patel