Well I did a basic tune-up (spark plugs/wires/fuel filter/oil change) and now I'm getting an ABS INOP service light. What could I have touched that could cause this? Thanks in advance.

 

One very common cause is having the plug wires too close to the ABS control wires. If that doesn't fix it, try having it scannned for DTC's

 

Probably simple. Since the passenger side plug wires are such a PITA to get to , you probably unplugged the pass side ABS sensor wires. Trace it back from the pass front wheel, make sure it's still plugged in.

If that isn't it, do the same at the driver's side.

 

It was the driver side plug wires. Rerouting them fixed the problem. Thanks all for the responses.