EOT sensor help

[92 Ty 1173]

Ok, so 1st of all I'm new here but somewhat familiar with the 7.3 because my boss has nothing but them. So we recently bought a '00 F-350 w/ 240k miles. After we got it we had 2 codes. 1st was an exhaust backpressure code. Pulled the sensor and the tube and found them to be blocked. Cleaned both of them and all is fine now. 2nd is the EOT sensor low circut input code. So I switched the EOT sensor with one from one of our other trucks thinking it may be the sensor. Not the problem, still getting the code and also getting the eratic engine behavior that comes along with it. The truck started fine this morning after I switched out the sensor, temp was around 28 outside, came to high idle, exhaust gate closed for warm-up, all good. On our Edge Evolution it showed 33 degrees for the EOT and after warm-up it was up to 120-130 degrees. Left it warm up for 15 minutes and went down the driveway and the damn light came back on. We have had the truck for about 3 weeks and there is no rhyme or reason as to when the code comes on. Could be right away or 20 miles down the road, and is sparatic while driving. So my question is, what and how do I test next?? Is there a way to test at the plug for voltage from the ECM? What would/should I see? Any help would be great, really don't want to take it to the stealership. Thanks in advance.

[92 Ty 1173]

I did some more testing yesterday and found that with the key on I usually have 4.8 to 5 volts on the one side of the EOT plug. I wiggled the plug and found that the connection was loose inside. I pushed the wire in and seemed to temparily fix it. I would like to replace the plug if someone could point me where to go to get the pigtail. But after that I stilll had the EOT sensor code. It seemed to be worse when shifted into reverse. I can clear the code when in drive and it would clear and then return a few minutes later. While in reverse I couldn't clear it at all. The engine will "chug" and surge then trip the code again. It sounds like I have an EFI "lope" setting on the truck. I watched our tuner in dagnostic mode and the EOT temp will go crazy, ranging from the correct temp then bounce around all the way up to 250-260. When the code light comes on it will stay at 212*. ECM default temp?? This thing is quite frustrating and I hope someone can point me in the right direction. My next move is to go through the harness and look for a crack or break in the wires. I really don't want to do that. Please help!

[kaya@bernhausen]

sounds like the issue is either with the pigtail or sensor. or both. try replacing the sensor first and see what it reads. if still erratic, replace the pigtail as well.

[92 Ty 1173]

Already did the sensor. Gotta find a pigtail to put on it. Anyone know if I can get one aftermarket?

[92 Ty 1173]

Nobody has any other suggestions? Is the eot circut tied to any other sensor? Any help would be great.