I have a few things I was curious about concerning Limp Mode, specifically in my 1JZ ECU. Just a quick background, I have a 1JZ swap in an '89, Holset HE351, basic supporting mods, and a MAP-ECU2 to tune with. I have the car running without the O2 sensor plugged in. I do have codes 21 & 25 which I'm pretty sure are a result. The car is running a little rich like expected and I haven't tuned it yet. I've heard with the O2 sensor unplugged the ECU will pull timing and be rich. What I'm wondering is whether it's a constant thing or changing. By that I mean does the ECU just retard the timing a set level across the board and add a certain amount of fuel? If so, could I theoretically add a certain amount of timing across the board and then tune the fuel to what I want. Then I wouldn't have to worry about the ECU constantly trying to reverse what I do. My turbo spools really fast (only 9 psi for now at about 3100 rpm's) and I can't have the ECU constantly trying to achieve stoich while in part throttle boost. Any help would be appreciated.
