hello

i have this issue when i am about to stop at stop light or if i let off  the gas pedal the rpm will start fluctuate it will go down and up several times sometimes the engine  will stall

my car is a6 c5 2.7t

thanks prj I appreciate your quick reply

i did Pressure test i found leak from the intake manifold gasket replaced the intake manifold gasket didn't fix the issue
 i replaced the crank position sensor problem solved
now my car back as  it was befor and the p1127 and p1129 are gone
but i have another probem which is the ldp fault code
 EVAP Leak Detection Pump: Open Circuit P1473 - 35-00
i tried to codeout but it didn't  work
here is what i did
CLATEVE =1
CLALDPE =0
CDLDP =0
CDTES =0
my ecu running mbox file