130,000 mile on 2002 Passat wagon. Recommeded two new catalytic converters at last maintenace check, plus now have problem with lost of coolant–no apparent leaks. What could be the problem. Should I repair both?
Tests for a leaking head gasket should be performed. This consists of a compression test, cooling system pressure test, hydrocarbon test for the coolant, inspection of the spark plug tips, etc.
If coolant is being lost into the combustion chambers it can very well ruin the converters.
I’d try to determine if there’s a head gasket fault and make a decision based on the results of that.