Asked for help last year. Engine was stalling ( after reaching Op temp ) when coming off gas to slow down. Would restart and run till next slowdown (not good) Independent VW mech couldn't solve.Replaced pre throttle body pipe!!. Over time problem went away (ish). Turned up again following cambelt replacement (nearly blew engine, tension roll seized- another story) After detective work on tinternet,turns out it's been the Mass Airflow Sensor after the air filter housing . By unplugging it ,engine ran fine. This sensor sends info to the ECU to adjust fuel/air etc for optimum running, a failing one won't do this, therefore causing this stall problem.Won't necessarily show as diagnostic fault code or light ECU lamp in dash (mine didn't) Can be cleaned using MAF cleaner, might work and solve issue as sensor tip gets dirty over time, however do NOT touch tip (clean every 30000 miles apparently) but I've replaced mine with a patent one from Europarts ( £49 after 25% discount or original BOSCH £ 134 less £24 part-ex less discount. Look up "Europarts discount codes" before buying for up to date promo codes ) You get the sensor and airpipe section its fastened in, but I just swapped out the sensor ( 2 security type Torx screws , so you need the right tool to get them out )Plugged it in, job's a gud'un car running like a train, ECU didn't need programming I,ve gone on a bit but i hope it helps anyone in a similar situation , Cheers.