Vehcile speed sensor

New to the Volkswagen forum, tried searches for info, I'll try a post now. Just bought my son a 96 Jetta Trek, 2.0 manual tranny. previous owner had just installed a clutch and veh speed sensor (so she says). Supposedly a couple people used OBDs during their look over of the car but declined buying. When I bought it it ran great and no service engine light lit. Got a temp reg (in CT you need emission check before final reg) put a muffler on it a couple days ago, ready to take it to a emissions station today and he comes home from school and the engine light is lit. Checked it at Advance Auto and it reads PO501 Vehicle Speed Sensor A Range/Performance, then 2 pending codes, PO172 System too Rich (Bank1) and PO103 MAF or VAF A Circuit High Input . Wouldn't be too bad if I just needed a new Speed Sensor ($30 bucks or so??) But a Mass Air FLow looks to be about $150!!. Could the pending codes be related to the speed sensor? Also being new to the Volkswagen scene, where is the speed sensor and is it easy to replace? Any help would be great!

Mine is a 90 - totally different, but - I would look for the vehicle speed sensor in the same place they are on most other FWD cars. On the 'differential' section of the transaxle, placed fairly inaccessibly between the backside of the lower transaxle and the firewall.
Northern Virginia is the same way with the registration; either passes emissions or you dont get the tags. Good Luck...

I'd clean your MAF with carb cleaner, it may take care of the whole problem.