[Black_GT]

quote:Originally posted by beachknight

From what I understand of the PT's computer is that it get its input for fuel air mix from the MAS and O2 sensors at 'regular' throttle positions and at WOT is goes into a bypass or loop mode and only takes the AIT for the mixture. Of course I have been known to be wrong from time to time.[^]

The PT's are a MAP based system. And yes, the computer runs in closed loop most of the time. When you hit WOT and it goes to open loop, it refers to a lookup table stored within the computer itself. It also hits open loop on initial starup and when decelerating for more than a few seconds with 0 throttle input. Anywho, this is a simple mod, the exact value of the resistor you need is 10k, 1/4 (read .25)watt resistor. make sure you get this one - a different value will mess things up a bit. (They're like 10 cents at Radio Shack) What it does is to fool the PCM into thinking it's slightly cooler than ambient, and to advance the timing 1-2 degrees. Good for a few horses on a warm day. I still wouldn't advocate it's use. It's fooling the computer into thinking it's colder outside air coming in, advancing the timing and feeding more fuel for the advanced timing...ALL THE TIME. Even at idle and when your roaming around in traffic it's throwing more fuel to get burned up when you really don't need it, so be prepared to lose 1-2 MPG. Oh, and on a cool day it's useless.