What are the symptoms of a clogged catalytic converter?
by Ben Pila, Jr.
Member at Large
The most noticeable symptom will be a lack of power. You step on the gas and your Z car doesn't get up and go. A badly plugged converter may not even let the vehicle go over 30 mph. The converter will be hotter on its intake side if it is plugged and may even have a dull red glow if the engine has been running a while.
Here's the simple procedure for testing for a clogged catalytic converter:
This is an indirect test - a better one is to use a backpressure tester. This is a vacuum/pressure gauge with an adapter, which allows the tester to be screwed into the oxygen sensor's socket.
At 3000 RPM, the backpressure should be below 3 PSI. You can buy these at your local automotive parts place for $25-30.