I bought a 1996 F250 4X4 automatic with a 5.8 (351W) engine (105K miles). Crawled under it and found the exhaust had been removed from the manifolds back with dual pipes and glass packs muffles. When I bought it - the engine started horrible - had to hold the gas peddle to the floor to get it fire then it ran horrible until it warmed up. I replaced the IAC valve and it now starts at the turn of a key but it idles pretty rough until it warms up - lots of black smoke and when gunned it will backfire. When it warms up the backfire is gone and the smoke almost disappears except when gunned extremely hard.
Now for the question - anyone know what they did to remove the catalytic converters? The oxygen sensors are gone. The check engine light doesn't come on now that the IAC valve has been replaced. As stated it runs very strong once warmed up but the plugs we removed were black and sooty. I am assuming there is a tune that tricks the computer into thinking the oxygen sensors are still giving a read out - otherwise the check engine light would be on all the time. Should we run hotter plugs than standard or is that asking for more problems? Or just drive it like it is and don't worry about it cold running antics.
I bought it for my son and he LOVES the sound and is in the process of installing a flatbed on it. This summer it will be the main hay hauler.
Now for the question - anyone know what they did to remove the catalytic converters? The oxygen sensors are gone. The check engine light doesn't come on now that the IAC valve has been replaced. As stated it runs very strong once warmed up but the plugs we removed were black and sooty. I am assuming there is a tune that tricks the computer into thinking the oxygen sensors are still giving a read out - otherwise the check engine light would be on all the time. Should we run hotter plugs than standard or is that asking for more problems? Or just drive it like it is and don't worry about it cold running antics.
I bought it for my son and he LOVES the sound and is in the process of installing a flatbed on it. This summer it will be the main hay hauler.