V-10 motor, exshaust pipes get red hot

The converter was melting, not coming apart. The whole exshaust has been checked (with a scope) and they say nothing is blocking it. They think it is running to lean. The pcm was remanufactored and that did not fix it.

They said that they have checked ever sensor, compression, etc. They said something about a timing problem. Over 50 man hours and they are stumped.

If the timing was wrong, wouldn't that show up with the computer scan test? Isn't the timing controlled by the pcm unit? What could be causing the timing to be off (wrong)?

Hello again, have not tried switching coils or anything else. Have not noiced any cylinders missing or running rough, but it did ping/knock when you have the gas to the floor trying to get up a big hill. Also before I had the convertor changed I checked for codes even though the light was not on, it had a code for number one cylinder misfire. Do you think the true timing counld be off?

Hello again, still need help. As far as coils and injectors go, the engine does not to have any missing cylinders. Everything seems to run ok. But on the highway, trying to get up the bigger hills, with the gas pedal to the floor and loosing speed the engine pings or knocks. Also before I took the camper to be serviced, I checked for any codes (even though the check engine light was not on) and it had a code for a number one cylinder misfire. Could that have anything to do with the true timing? Any thoughts?

Do you think the timing could be off from when it was made? It only has 23,000 miles on it and I don't think it has ever driven to far at a time.I think it got worse as the converter plugged up (melted). Just a thought. THanks for any help, it's real puzzeler.