new to forum need advice a few months ago I purchased a gmpp lsa with gmpp standalone engine harness the car already has a built hughes performance 4l80e with a tci tranny controller I want to keep the tci controller but according to the gmpp engine standalone instruction sheet it says you must use a gmpp tranny standalone harness according to psi they think its just bs need your advice

 

Does it say you need to use their harness for warranty?