Posted to Technical Discussion Forum on 8/8/2015

Had this vehicle come in with turbo issues. Replaced turbo, with a bad reman, had to do the job again! After 2nd turbo R&R, I received codes for MAF sensor, & turbo worked until code set. Replaced sensor, got same codes back. Went back to when I first opened the hood & noticed the MAP sensor didn't have a harness plugged to it, but did see another sensor, same part number, plugged in by the EGR valve... I moved this harness to the MAP sensor, where AllData says it's located, at the pipe to the cooler... Codes are gone, turbo works great. My question... Why two MAP sensors, only one connected, what is the other one for, & which is the correct one for operation? The harness seems to be more natural where I put it, but there's still another MAP sensor on the opposite side of the EGR valve, why?

John Keesling
Technician/Shop Foreman
Columbus Auto & Truck Service
Forest Lake, Minnesota, USA