po106

Was getting code daily, so i changed the MAP sensor and the code stopped for a while. I has came back but not as often, only on the highway when cruising to or from work. Where do I go from here on testing?

Was getting code daily, so i changed the MAP sensor and the code stopped for a while. I has came back but not as often, only on the highway when cruising to or from work. Where do I go from here on testing?
Can we assume that this is on your 99 Blazer? Anyway, check the grounding points for good contact. FireWall to engine block and the ECM to the chasis.