Chassis 221,
I did run it with the O2 sensor removed from the bung. Car ran much better allowing me to rev to 3800 rpm with no CEL. After changing the remaining 3 sensors I received the same codes. Then I cleared codes, and let car idle. First code that came in was misfire on cyl 1. Was planning on swapping coil pack to see If I received a misfire on the other bank, but it seems to be pointing to a clogged cat. I've never heard any rattling on the cats since owning the vehicle.

Mike

 

If you have an infrared temp gun see what your cat temp is before the cat and again after.
The temp should be roughly 100 degrees hotter when exiting the cat.
If it's 50-100 degrees colder exiting the cat, you know it's probably plugged.
When making the test keep the gun at the same distance from the exhaust pipe.
Also keep the gun the same distance away from the cat (before and after)
I usually keep the gun one inch from the pipe and 1 inch before and after the cat.
Make sure the engine is thorougly hot and then take your measurements.

Another quick check (if you can get the RPM's up) check the pressure exiting the tail pipe, feel the pressure at idle, raise the RPM's, you should be able to feel the increased pressure exiting the tail pipe.
Careful it may be hot!!
If the pressure barely increases it indicates a plugged cat.
When and if you replace the cat, verify there is no debris that made its way from the cat to the muffler.

 

Plugged cat was the problem. Replaced it and car runs. Car still seems to idle a little rough, any idea what this could be? Not throwing any codes. Could a MAF insert cause this? I got mine from german star auto parts.

Mike

 

thanks for the info on what the fix was.