Our 99 Volvo V70XC recently had a CEL. The dealer diagnosed the problem as an exhaust manifold gasket leak that had ruined the catalytic converter by allowing outside air to enter the exhaust stream. The Diagnostic code was ECM-4801. My question is: would a manifold gasket leak such as this cause damage to the catalytic converter, and what problems could be caused by not getting the converter replaced immediately as recommended by the dealer? The dealer also recommended cleaning the turbo “oil flame trap” and replacing the seals. Is that also necessary?
The exhaust manifold is under pressure from exhaust going OUT thru it. HOW can outside air get in in the first place, much less how could it harm the cat? I think it’s a bogus diagnosis. You need to find an independent mechanic that knows Volvos. There is one out there. Check right here: http://www.cartalk.com/content/mechx/ The turbo work is good preventive maintenance, but there is no reason to pay dealer prices for it. A new one runs about $1200.