I have 2 problems i been working on for a while on a 97 f-150 with 5.4 engine. First, my temperature gauge pegs out into hot after the engine is running about 2 minutes.....some tell me this is the gauge itself and the only solution is a whole new cluster. Second, my check engine ligh is on. Just had plugs changed, new egr valve, and o2 sensor changed. The code reader says there is a low reading on the o2 sensor but i changed it twice and no difference. I also found out the manufactor code says i have a vacuum line on the egr valve that is clogged or unplugged but i checked that and is fine..... please help!

 

Your ECM may have crapped out on you. Did you reset the computer after checking the codes?

SL

 

I wouldn't go to assuming the ECM was faulty. No evidence of that.

Post the exact codes, perform a SEARCH on them, and you will likely find that they are common faults with equally common repairs.

I would suspect the ECT sender is defective before the instrument cluster for the temp guaage problem.

Steve

 

I wasn't assuming the ECM was bad. I was merely saying that the ECM MAY be bad. That's why I asked if he cleared his codes out.

OK, he's getting codes referring to his EGR lines and O2 sensor. Lines are fine, O2 sensor replaced twice. If the codes aren't erased, obviously, they will still be there. Let's assume the wiring on the vehicle is OK. IF the codes were cleared and said components are either new OR checked out and are fine, and the ECM is throwing the same codes, the ECM may be malfunctioning.

SL

 

well i guess i overlooked something....somehow there was a tube off the DPFE sensor so i cleared the code and now runs fine..... only problem now is the water temperature gauge is still pegged on hot. the truck is not overheating and i already replaced the temperature gauge sensor so what now?????? a whole new cluster?