Four problems related to manifold/header/muffler/tail pipe have been reported for the 1999 Ford Explorer. The most recently reported issues are listed below.
When the automobile(Ford Explorer 1999 sohc v6) is in cold weather and you start it it seems to misfire or act like there is an air leak. I have read several post on the internet and people seem to see this problem alot on certain year Ford Explorers. The have said that it is caused by an air leak around the exhaust manafold that only shows up when the engine is cold because the part is shrunk and does not fit but once the car warms up the part expands and acts as if there is no problems. When starting the car in warm weather you never see this problem. I have not had this fixed on my car since I park in a garage I rarely see this.
While driving engine reached high temperatures due to intake manifold failure. Coolant went inside the engine.
"check engine" light came, but car appeared to run/perform normally. When the light came on, I was low on fuel. Had dealer check, reported taht I needed new fuel pump, there were leaks at intake gaskets & cost to repair would be about $1,200. Second scan by another auto shop could not get the same computer "codes" as dealer. "check engine" light was reset. On 1/24/2002, when fuel tank was very low, "check engine" came on again. Not convinced what the problem is! I am certain that water in the fuel is part of the problem. I am not convinced that a new fuel pump is needed.
Was smelling fumes inside vehicle. Noticed fuel from exhaust pipe. Parked vehicle & checked underneath & saw the leakage. Have taken vehicle to dealer. Was informed fuel injectors were open. This was causing the leakage problem.