Flex fuel de-conversion questions

[pjtoledo]

starting with my 2000 3.0 which is of course a flex fuel system, has the sensor in the fuel lines that sends the alcohol percentage to the PCM.

a couple years later Ford did away with the alcohol sensor and then used the O2 sensors to tell the PCM to add more fuel (very abbreviated version)

Since my alcohol sensor failed a few years ago I've been running on an FF simulator. works great but mileage is kinda suckie. Yea, I know, its a 3.0 in a 4x4 ATX.

Questions are....

what was the year change to non-sensor FF systems,
can I just swap in a newer PCM that doesn't use the FF sensor?
any big changes to the wiring harness, other than the sensor wires won't be there?
and of course,,, what about PATS, would PATS still work if the PCM is swapped?


Thanks
Perry

 

[stmitch]

I think they eliminated the flex fuel sensor in 01. That seems to be when they made several changes to the 3.0, and I'm guessing that was one of them. They were definitely gone by 02 though.

PATS is tied to the PCM, so you'd have to either pay a dealer to reprogram your keys to match the new PCM, or buy a handheld tuner and have the PATS deleted as part of a custom tune. The tuner might not be a bad idea, because you could have a performance or fuel economy tune written for it and adjust auto trans shift points at the same time, but it's pricey.

By the time you buy an 01+ PCM, and then pay the dealer for the PATS stuff, or buy an aftermarket tuner, you probably could've just bought a new flex fuel sensor.

Do you have any idea if there is any difference between the O2 sensors before/after they made the switch to having the PCM estimate the alcohol content? That could be an additional expense to consider if your stock O2s aren't able to measure the same parameters as the newer ones.

 

[Destroyer000]

i have a flex sensor if your interested. not doing me any good since i run 4.0s.