Volkswagen: rabbit dies at low idle, fuel pressure regulator, elbow grease

Question
i just bought an 83 rabbit convertible . had a tune up done , replaced both fuel filters , various belts vacuum lines and ignition wires. since then if i let the rpms drop below 1000 it just dies . the o2 lights been on since i got it but the mechanic reconnected the wire when he did the tune up. could that be it or does it need an idle adjust or should i just gut the injection system and switch to a carb like my 85

Answer
Chris

Start with a bottle of high quality injector cleaner like Techron.  If that does not do it, clean the throttle body.  When done, make sure it looks like new, both sides.  A good throttle body cleaner, some elbow grease and some patience should do it.

Rob

PS- Is the fuel pressure regulator ok?  How about the MAF?