I have a 2004 Volkswagen Touareg V8 the issue started when the vehicle started sputtering or kind of rocking a little so I plugged in that OBD2 reader it told me that it was misfiring all cylinders and the farm again I changed all eight spark plugs all eight coil packs from there I put in two mass air flow sensors I've changed all four O2 sensors I've replaced two flex hoses replace the PCV valve can't seem to find where the hose goes to the vacuum reservoir so I plugged it with the screw changed all added treatments still cannot find the problem the car still rocks idles weird and now I'm starting to smell fumes I'm wondering if the whole problem would have been or is my catalytic converter I'm starting to smell fumes in the cab looking for an easy fix