What info do I need to say at the electronics shop to get that transistor?( Q31) I managed to pinpoint this thanks to intense searching, but can't find specifics on this transistor other than its NPN ... And any other suggestions are welcome, or guidance as to soldering my ECU. Thanks H-T!

 

Try taking it to the electronics shop so they can see it, resistors go by the color banding on them, but im not sure how you can visually tell with a transistor.

 

I've gone to quite some stores already and noone has that transistor!! Is it necessary? My ECU is Chrome Tuned. Also, would Q31 on other ECU's be that same transistor? Can I remove it from another ECU? Thanks!

 

Ok so I desoldered that transistor entirely, and left it as it is... put my ECU back in its place, and I drove the car today for about 1 hour with absolutely no problem. WEIRD! lol I believe when it would get very hot here, it would make the transistor achieve and lose contact intermittently , causing the ECU to notice some bad wiring issue and entering BS LIMP MODE.

 

switch your EVAP purge and IAT plugs so they are correct. (they are switched at the moment, that's what caused Q31 to pop, very common issue)
replace your IAT, it's likely damaged or blown entirely because it's not made to have 12V across it.

There is no CEL for EVAP purge in OBD1, so no CEL for it being gone. BUT your EVAP purge solinoid is currently connected to the IAT input, which is making the car run like it's super cold out. (ie rich)

It's likely that Q31 pulled the power pretty low when it popped which can make the MCU either read something incorrectly or simply get screwed up.

NOTE: all P28/P06/P05's use the same Q31 (D1780) part.