Ford Ranger / Mazda B4000 6 cylinder 4.0 Liter V6 4X4 / manual trans Engine control unit Up for sale is a Working, in excellent condition Ford ECU As you probably know, this is a pretty hard one to find "good used" at a reasonable price. As always your best bet is to match the part number to the one on your original ECU. My list shows this may fit 1990-2000 6 cylinder 4.0 Liter trucks. XL5F12A650BEAThese are usually fairly reliable, however can easily be damaged by wiring faults or voltage spikes (caused by a faulty alternator). Sometimes a failure simply happens due to corrosion or high mileage use. A faulty ECU can cause problems ranging from a bad idle control circuit to random no injector pop signal (causes no start or random cut outs) & many others. Comes with a 30 day guarantee. See the details in the next page in the return policy.