Autothority chip = high idle
#1
Three Wheelin'
Thread Starter
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I had a set of authority chips from a 1987 S4 auto and I installed them in my 1988 928 S4 5-speed manual a few weeks ago. I noticed that the idle speed changed to 875-900 RPM (instead of 675-700). Still steady.
The only modification made on the car is the installation of a X-pipe without cats.
I swapped them back and idle speed returns to normal (675-700 RPM)![Confused](https://rennlist.com/forums/images/smilies/confused.gif)
I know that there is a chip for the 928GT and another for the 1987-91 S4 (the one I have).
But do I need a different one for a 1987-89 S4 with a 5 speed manual or I need to use the GT set?
The only modification made on the car is the installation of a X-pipe without cats.
I swapped them back and idle speed returns to normal (675-700 RPM)
![Confused](https://rennlist.com/forums/images/smilies/confused.gif)
I know that there is a chip for the 928GT and another for the 1987-91 S4 (the one I have).
But do I need a different one for a 1987-89 S4 with a 5 speed manual or I need to use the GT set?