I posted this in the tuning section as well since it relates to both kinda:

My SES light has been on ever since I done the engine swap in sig, and were cleared when I had it partially tuned because my o2 sensor on passenger side was out during tuning. Well I fixed that and havnt had the tuning finished and SES light came on again; I also went from a 3.42 stock rear to a 3.73 posi. When I installed my Aeroforce Interceptor gauges and did a code read, they were
p0171 - lean bank 1
p0174 - lean bank 2
p0740 - TC clutch malfunction
p0785 - shift timing solenoid malfuntion
p1860 - TCC PWM solenoid circuit

Transmission in sig also seems to be acting weird, locking and unlocking almost like it is slipping, and when I decelerate, RPMs will drop and out of no where the converter will lock up. It also feels a little looser sometimes when starting out. Im hoping it might be an unplugged solenoid or loose wire but wont have a chance to check it out until tomorrow. I dont know what could be causing the lean condition, im thinking maybe exhaust leak due to the long tubes, or maybe vacum leak, or maybe something with the MAFS. Any ideas on tranny or lean conditon?

 

I also just went underneath the truck and dont see anything out of the ordinary as far as unplugged, loose, or damaged wires coming to and or from the tranny; most of my focus was on the driver side of tranny where 2 harnesses plug in to the side that the transmission position sensor is assmebley is on.

 

Your lockup isues could be related to your o2 issues or engine missfires. Also when you changed your rearend did you change the tune for it. Sounds like you have some issues to straighten out.

 

Vince, I didnt have the tune changed for the rearend so that could have thrown everything else off. I will have to get the tuning finished since I did the rearend and replaced the bad 02 so I hope that gets it back to normal lol

 

I think your heading in the right direction. Even a change in tire size can cause wierd things to happen. Good luck to you and let us know if there is anything we can do. Vince