Audi Repair: Audi A4 2.8 00, vacuum hose, obd system

Question
My 2.8 has had the check engine light on for a while but recently the ABS indicator light started flashing. It failed emissions with a P1423 Manufacturer specific code. I took it to the dealership a week and they referenced the ABS Module replacement for $1151! Have you seen these errors together and are they related?

Answer
hello
Your car failed emissions because of P1423 not because faulty ABS module. But, on many audis if ABS madule goes bad , OBD system ( which is engine) can not be seen. So , you can replace module (part about $450) or disconnect Abs module and go for inspection. If there is no any faults - you good , if there is fault (like P1423) - you failed.
P1423 - is for secondary air system . This system works similar to EGR on many other cars.
On 2.8 engine most of the time vacuum hose brakes on one or both combi valves which are on the back of the cylinder heads. Onece this is fixed - most of the time system will work OK.
good luck           Greg
$1151 - I think is a lot for ABS module . We charge about 2 h.