fluctuating idle on 2003 passat

@mcclaine67 , Adrian, there are quite a few things that could cause your idle problem. Dirty throttle body, dirty/faulty MAF sensor, Vacuum leaks from hose off/cracked or bad seal at intake or throttle body base, O2 sensor faulty, temp. sensor faulty,etc.etc..

Get the car scanned as a first step to see if there are codes present that may lead you directly to the fault. Some of the auto parts suppliers offer free code reading like Pepboys, Nappa, Advanced auto parts,etc and some of the guys are very knowledgeable and may have seen the issue often and put you on the right track. If not comfortable working on your vehicle have a good tech. have a look, diagnose and estimate repair.

Good luck.

I hope this helped you out, if so let me know by pressing the helpful button.