Originally Posted by FattyAzzBonneville
...... i can guaruntee
Not to say it'* not a cat, however w/o being a mechanic and running the appropriate tests, you can't guarantee a thing.
First thing to do on a car with issues is bring the general maintenance items up to par. In this case the plugs and wires were replaced and found to be in horrible condition. If they were neglected that badly, what are the chances that the fuel FILTER is also due for replacement.
The FSM points us first to general maintenance, then to further diagnosis. Don't condem the cat unless there was a bad O2 sensor previously as the O2 is the cause of 95% of all cat failures. Does the exhaust sound restricted? Does it seem to be hungry for more fuel, has the filter been neglected, could the pump be weak because of that. Has a proper test been done to justify any path or direction?
A fuel filter and pressure test gauge is around $30 and installed cat can run roughly $100~200.
The question is.. should we help diagnose this or simply shotgun this persons weekly paycheck on parts that we haven't fully diagnosed?