Hi All,
I've been pulling my few remaining hairs out over this for awhile now.
The car is a turbo 5.3 with blow-through MAF and the 3 bar OS. The engine itself is stock, and idle issues and this issue (which may be related) aside, runs nicely.
I was finally able to catch the baro dropping while the engine was running in a log. I'm at sea level, so 101kpa is correct. It dropped to 90 kpa a minute or so into the log and the MAP went up by 10kpa. Fuel trim chaos ensued.
Any ideas what could cause this? I thought the baro was read at key on engine off just before starting the engine, then remembered for the drive cycle.
Thanks!