I still have this problem with my rex its been since early feb and still no fix...

I put my motor in and when It first started it ran fine for about 20 mins, then I turned it off. When I started it next the engine runs very rough 100-200 rpm, a/f is lean, throwing a code 68 and my main relay clicks non stop. What I've found is when I unplug my map sensor and run the engine the main relay doesnt click and i get actual idle somewhat back. I have a 3bar map and a stock map as well. either one when plugged in makes the relay click. Everyone and their mother has told me to check the grounds and each one has half an ohm to chassis ground. Its been a month and i've had enough, i hate asking people for help but i cant think of anything else.