Hi scotty i live in europe i have an audi a6 3.0 tdi quattro 2006 it has 200k miles on it and it has revolutions variatons when you step off the throttle for example on downhills when rpm go 1000 rpm they start jumping a couple of times from 1000 to 1500 rpm and then it got stabilized in vcds vag com scan if shows p0401 code cloged egr valve but others say it may have torque converter but it changes gears smothly what do you say?