misfire code, hot exhaust even after new cats

[disco1776]

I had the CE light come on and it read "cyliner 7 misfire". Replaced spark plugs and wires, and then the cat convertor began glowing red hot. Replaced the cat and the mechanic is telling me that even after the convertor was replaced, the exhaust is still doing to same thing. He is telling me that I am just going to burn up another catalytic convertor if I drive it. What is wrong with the Disco? I dont know what else to try.

 

[barefoot]

hmmm. cyl.7 misfire...could be sticking valve, bad/clogged injector or worn cam lobe...what year and how many miles?? try running some seafoam throught the plenum and see if that doesnt help... and no i would not drive it if the cat is getting that hot.

as a side note, i once kept getting a cyl 1 misfire because the spark plug was not tight...it had hit a tight spot and felt like it was tight but really...when i got the torque wrench out, there was about 4-5 more turns til it was right.. just a thought.