The fact that you mention your vehicle is a Volkswagen automatically
says.... Yes it's the CAT... assuming it's a non-EGR valve equipped VW and
only after inspecting the fuel and ignition systems. An intrusive CAT test
and Back Pressure/Vacuum test can be performed to verify the CATs condition.
A 5 gas analyzer will be needed to take exhaust samples before the CAT and
after the CAT to measure the difference in HC, CO, and NOx. This test will
determine whether the CAT is defective or not.
posted by SmogTips Support
