the dreaded throttle control error codes

[Bob_n_Cincy]

Rick, do you have have a actual wire from battery negative to engine block? Or are you going through the chassis?
Bob

[FFRWRX]

Rick, do you have have a actual wire from battery negative to engine block? Or are you going through the chassis?
Bob

My ground lead uses the frame. My reasoning is:

1) Millions of production cars do it this way and it works; including Subaru I imagine (though my car came with the donor stuff already stripped out so I don't know for sure).

2) The car starts fine which means the ground conducts a couple hundred amps without issue.

3) The ground lead at the battery is short and goes onto the frame; clean connection. There is a robust lead from the engine block to the frame at the rear.

4) If it was a ground momentarily losing contact, would it cause this exact symptom every time? Honestly, I have no idea.

I could run a booster cable clamped on the battery and the other end onto the engine, if I can figure a way to do that while leaving the car drivable; hood and rear deck lid partially open.