What is causing catalytic converters to clog?

LEODAJIM

MEMBER
2004 FORD ESCAPE
6 CYL
4WD
AUTOMATIC
95,000 MILES

2004 Ford Escape XLT, 3.0L V6, 98,000 miles.

4,000 miles ago, I had a new rear catalytic converter put on my Escape b/c it had become clogged.

I recently replaced all six plugs and coils b/c a few cylinders were misfiring. After doing that, I was soon was getting engine codes from two O2 sensors for 'lean' gas. So I checked for vacuum leaks, verified all hoses and connections were ok, the manifold bolts were torqued correctly, and I could not find any leaks. I replaced the PCV valve (the old one barely rattled anymore)so I am hoping I fixed the 'lean' engine code issue.

Now, the same converter is clogged again after only 4,000 miles. My questions.

Did the converter possibly become clogged b/c of the cylinder misfires and 'lean' gas issue?
Are there other underlying issues I could check out that may be causing the converters to fail?
I am not sure if I have solved the problem with new plugs, coils and a PCV valve, or if there is something else going on that will destroy another converter.

Thanks to anyone in advance for your expert advice.

1 Reply

LEODAJIM

MEMBER
25 POSTS

Update to above.
The muffler shop tells me that the catalyst in the converter actually melted down and broke apart. From my limited knowledge, I think that means my engine is running too rich. Again, I don't know if I have already fixed the issue by replacing coils, plugs, and the PCV valve. I don't know what other things to check and/or tests to perfrom to make sure there is still not an issue with the engine, thus ruining another converter. Any expert advice is much appreciated.