C Beard

I've got a 02 ws6 with a 408 and a t56. Car idles fine on startup, around 900 rpm. Once I drive it a few minutes the idle goes up to 2,000 while the car is rolling (in neutral) then drops back to 900 as soon as the wheels stop turning. It's throwing a wheel speed sensor code C0245 and also a couple 02 sensor codes P1153, P0133 and P1133. I'm assuming the wheel speed sensor code is from the back tires being taller than the front? Also assuming I have a bad 02 sensor or possibly two. Question is which one is likely to be causing the weird high idle or are any of the codes shown at fault? Seems like a bad 02 sensor would cause idle problems no matter if the car was stopped or rolling. Anyone else experienced this or heard of anything similar? Car does have headers.

SouthernRex

I thought that was how all of them worked, to help with engine speed during deceleration since it's throttle by wire. I could be 100% wrong, but once I apply the brakes my engine speed drops dramatically, but it hangs in the 2000-3000RPM range gently dropping as I coast.

A4 here, though.

Leviss

I'm having the same issue. Have you figured out the problem? My car won't drop to idle a few seconds after I stop.. It just holds 2k rpm and right before I take off again it drops to 1k idle.