Need help here. My dad baught a 1989 travelaire RV camper which has this ford econoline 460 engine, V8 7.5L. Thing is it runs very rich (5-6 miles per gallon) and alot of black stuff like unburned gas is clearly marked on the exhaust pipe. So he changed the O2 sensor but no improvment at all. But what I did notice in talking with him was that if the O2 sensor is disconnected, there is no check engine light!!! From my understanding, OBD1 systems would set off the check engine for a disconnected O2 sensor....Right?
Could the O2 sensor have been bypassed? anyway of knowing why the engine does not cryout a problem with no O2 sensor? Where would the engine computer be on ford trucks.