randomly dies p1659 wont start 2008 fa5

[turbofa5]

i just replaced and rebuilt my transmission in my fa5. it is turbo and the motor is forged. ive built everything on this car. never had this issue. after getting it running again. I took it down the block for a car wash. as soon as I hit the dip for the entrance the car just died. flashpro would not communicate with the ecu and would not start. no fuel pressure. I unplugged and replugged the pcm and got flashpro to read the pcm. upon my first attempt to start I got a cel dtc for p1659 - unknown dtc. I further searched and came up on it being a etcs relay malfunction. I was able to swap the relay with a known working one from a friends fa5. with his in mine it does nothing. but when I put my etcs relay in his the throttle wouldn't go past like 30% throttle and was high idling. the pcm will connect to flashpro and accept a flash. but that does nothing to start. the fuel pump just never primes. I was stuck at the car wash from 7pm to 2am trying to fix this. I unwrapped the harness from the ecu and tried tracing for a short to no avail. im hoping my ecu isn't gone and im not sure I can believe multiple relays can go bad over a dip going 2 mph over. also to add flashpro would show the % of the throttle peddle but the throttle body itself would stay at 8%. but any idea as far as what may have happened or experience in solving a similar issue is much appreciated. im at work so I don't have access to the car currently to upload a log of cranking.

[Spunkster]

Try unplugging the primary oxygen sensor completely and see if it starts properly.

[turbofa5]

I will give that a try as well as swapping known working fuel pump relay inside the car. this is my only vehicle and im borrowing my friends mugen lol. any reason why you suggest the primary o2?

[Spunkster]

I have seen a damaged one do something similar.

[turbofa5]

fair enough. I will update when I get off and post a datalog of cranking