Using SD OS i was having problems with fueling changes having no effect on AFR. It would effect it briefly then correct itself. I assumed i was in SD mode by loading SD OS.
I went to my MAF table and zeroed it out. Truck would start but run poorly. So i went to DTC and by default with SD OS P0103 code was set (No error to report) i set it to (MIL first error)like i normally do to force MAFLess. RTT works great now. Just a simple not in SD mode was all it was. This may already been covered if so I apologize for duplicate post.
2002 silverado P01 ecu