Ihatespeedbumps

I seem to recall you need to match P/N's when swapping those radio units.

No radio code for this model.

This seems less like a build thread and more like you need help topic. Moving to Performance, I can move back if necessary.

Verified fuel pressure at the rail with a mechanical gauge?

Codes stored?

Your torque pro app isn't going to give you residual pressure with the key off.

Doubtful the injectors are going to do anything. I would measure the fuel pressure at the rail with a mechanical gauge, should be around 400kpa at idle. You also need to check residual fuel pressure, should not drop more than 100kpa in about 20 minutes.

I was wondering if you finally sold it. Glad to see you are still around.

Did you use OEM plugs and coils?

Awesome! Glad it got resolved!

I think at this point you are going to need to hook up VIDA and see if the REM is online and what codes have been stored.

Disconnecting the battery won't discharge the capacitors in the REM. It's a large square terminal with a 10mm bolt through the center.

Remove the large power connector on the REM for about 1 minute and re-attach, this is going to re-boot the REM

I suspect you might have a broken wiring harness at the tailgate hinge and you didn't notice until you started installing the trailer wiring. Pull the braided plastic sheathing back around the harness at the drivers' side hinge and see if you have any broken wires. Pretty common problem.

Tom, sounds like you've got a bad synchro in your current transmission. To my knowledge, there are no serviceable parts inside the M66 so unit replacement is the only option.