So the check engine light isn't on, but I've had my truck scanned twice now and they still show a p1247 code. You can hear the turbo when taking off from an idle, but it doesn't pull like the turbo is actually making boost. Once it hits 2,000 rpms in 2nd gear or 3rd/drive, it'll all of a sudden start pulling hard. This morning on my way to work, I'm cruising down the road and start pulling a hill. The truck kicks itself out of overdrive back into drive and sure enough it's at about 2k rpms and pulls hard and fast enough to slow back down to the set cruise speed. Should I just replace the MAP sensor??? Every shop I ask wants to scan it it for 65 bucks. I don't need the damn thing scanned. I need it fixed. It's my daily driver. Also, when floored from a dead stop in the first 2 gears, as it gets up to 2k and higher, it'll make a loud whistle when it starts making boost(not a turbo whistle, like a vacuum leak whistle almost like a dog whistle, really loud and high pitched). Is it possibly a boost leak and the whistle is from the air rushing past where ever it's leaking?