you only loose passing gear when you are cruizin in 4th at 70+mph and try to slam on the gas it wont go back to 3rd for that passing gear <-- thats why wiring a switch is good.

all you do is just cut wire 63 (orange with black stripe)from the ecu and either just leave it and tape the cut wires up, or wire in a switch to it, so you can turn it on and off. I will do a write up if you want. This only works on automatics with the TCU seperate from the ECU. basicaly anyone with a pin 63 thats orange with a black stripe.

like this

Stock
TCMpin10--------------pin63ECU

Modified
TPMpin10------Switch-----pin63ECU
thats it

1998 dodge avenger 4 cyl AT
Mods are:
Not enough