Well Drift Office is throwing in the towel. They've tried everything short of rebuilding the engine harness and consulted several other tuners who have a lot of experience and they are all clueless about my problem. With my luck it'll be some old wire that's cracked and causing a short or something. Drift Office is charging me a very fair rate for the work they've done and I am very gracious for all the hard work they've put into my Supra. I'll be picking the Supra up soon and having it towed to BIC Performance where Bill Bowering will work his magic and remove and rebuild my engine harness. He'll check everything with a fine tooth comb, get rid of anything that isn't needed (i.e. remove any unused wiring including depinning the connectors so there is no trace of the wires) and convert my harness over to sequential injection since that will be much better. If that doesn't fix the issue then Bill will continue to work his magic until him and Randy have figured it out. Again, I am very grateful to Bob and his staff at Drift Office for all their hard work.
