Anyone know anything about ECU/ECM's

[Mitchs07explorer]

I think my engine comp might be faulty. I have weird tranny slip that won't go away even after rebuilding the tranny and the only thing that solves it temporarily is unhooking the battery to reset the computer. that will give me several hundred miles before it starts to slip again. I don't get the best gas mileage as its on the low end of the spectrum but 90% of my driving is stop and go with minimal highway driving. Also my CEL used to pop on all the time giving me a 442 code which is a small evap leak.

I changed my filler cap with an OEM cap and I replaced my fuel filter with a quality filter. That stopped the CEL from coming on as often but it still pops on once every month or so with the 442 code. Granted I've never had a smoke test done to see if I do have a leak somewhere in my evap system but the CEL only comes on so sporadically now I don't know what to think. It'll pop on when I'd filled my tank a week earlier and still have half a tank of fuel left. Anyway I'm wondering if anyone might concur with me that between the weird tranny shift between 2nd and 3rd that only unhooking the battery for and hour fixes, the lower fuel mileage and the CEL light popping on more than it should, should I have someone test my ECU? Opinions please....

 

[BootyDo]

When you say Tranny Slip, what are the symptoms? As in, does it happen predictably between the same two gears at a certain RPM on an incline, trying to rev, trying to maintain a constant speed, etc?

Also, and maybe someone can add more, but I thought the 442 test only cycled when a tank is between 1/4 and 3/4 full. That might explain why you're not seeing it all the time if that's true.

 

[Mitchs07explorer]

When you say Tranny Slip, what are the symptoms? As in, does it happen predictably between the same two gears at a certain RPM on an incline, trying to rev, trying to maintain a constant speed, etc?

Also, and maybe someone can add more, but I thought the 442 test only cycled when a tank is between 1/4 and 3/4 full. That might explain why you're not seeing it all the time if that's true.

It is fairly predictable and only happens between 2nd and 3rd gear when accelerating up to speed. It's not noticeable when accelerating up to say 25mph but if you're at a stop and you go to accelerate up to 40mph to keep up with traffic it's more likely to happen. It never happens when just maintaining speed and it's only more noticeable on an incline but the incline doesn't necessarily make the slip any worse. A certified ford mechanic that I talked to online mentioned the possibility of a faulty speed sensor and I haven't had a chance to look into that yet, I just don't know what to think.

That's interesting about the 442 code only showing between a 3/4 and 1/4 tank. That does make sense as it would trigger a week or so after fill up. I might just have to have the smoke test done.