car is a 2000. i found this forum while searching and it seems like there are a few guys on here with some serious knowledge so i thought i'd post it up. problem im having is the car will idle and sit at 2k rpm's. sometimes it steadily climbs to 2800, then drops to 1500 then 1000, then settles at idle. there are times its normal (usually when the car is cool). or other times it just sits at 2k. i can blip the throttle and get it to come down but that only works so often. the rpm gauge, when it does return to idle, it is very slow. it never drops like a normal cluster. also in between shifts it "surges" forward a bit before dropping down. great for quick shifts lol but not a dd. ive replaced the maf and that code went away. now im getting vag code 17549/P1141/004417 - Load Calculation Cross Check: Implausible Value . says its either a maf problem or check for vacuum leaks. could a vac leak be intermittent like that? would a blip of the throttle work on a vacuum leak? im just completely stumped. getting that one code, nothing else. any help is appreciated guys.

 

I would firstly ask what car do you have that has a 6 speed v8? I thought all the v8s were automatic? If its hanging in the right idle range when its cool, I would say that maybe there is a plug that unseats itself when it gets hot (seat expands or something). At the same time, some vacuum hose also expands when it gets hot and could unseat itself then, or maybe a crack in the hose.

I don't think its the maf. To the best of my understanding when the computer gets an implausible signal it uses a default value from the hardware tables and sends a CEL. I know that pulling vacuum hoses sometimes effects idle. Check all the hoses.

 

i swapped a 01e into my A6 4.2. i should also mention that vagcom group 005 would show the word "idle". when i pressed on the gas pedal it would say partial throttle. now when the car's idle would rise by itself while im holding throttle steady, vag com would say back to idle, yet my foot was clearly still pushing on the pedal. group 050 shows the rpm value its actually getting is 500 MORE than what is being requested. im gonna ckeck for vac leaks again