Hi george it seems you have a problem with the
air mass sensor or something affecting it's
performance. a healthy digital ams should be able to produce 8 to 8.5 khz peak. also an air leak can affect it's performance or a leaky egr valve. do you have a smoke machine to check these? does your scanner show the dpf differencial pressure this should be near zero on idle. also have you tried checking this fault with a different scanner? where are you situated?