Neutral safety/range selector switch externally mounted

Question

I just got this car it was given to me,,, it's got 4t65-e from the factory,, someone replaced it with another transmission and cut the wires to the pnp range selector neutral safety switch,,, and I believe they installed a 4t60-e trans in it or one out of an 01 impala,, all kinda codes coming up from trans to emissions control devices now,,, they bypassed the pnp safety switch and I believe tapped into the ECM harness also to get the car running and drivable,,, after code reset it'll respond and drive very well,,, but when mil light comes on usual within 8 miles of reset,,, trans will start to shift abruptly or harshly,,, TCC circuit comes up stuck in locked position,, then stuck in off position,,, the high/low range thru all the gears is coming up circuit A low voltage Circuit B high voltage etc etc,, EVAP codes galore for EGR valve circuit,, TPS sensor everything that's connected to the emissions control and trans circuit flashing hard codes,,, but yet the engine runs fine like nothing is wrong at all,,, HELP PLEASE!!! what can I do about this?? Limited equip to use but have most of the knowledge when you what where and how to check systems,,any help would be greatly appreciated i can't afford to take to a shop on SSI disability low monthly income thanks Vernon aka ghostwalker

Comments

If they tapped into the pnp as you say , than I'm guessing its to bypass the starting system.  If I'm right than that normally triggers the theft .. 2 things I see , a bad valve body to tcm or a pcm problem.  Best bet, pcm.