02 Tahoe - change ball joint, now getting ABS light

[70c-10]

I changed the lower passenger ball joint and now the ABS light is staying on.

I cleaned up the mounting surface for the sensor to make sure it is seated properly. I have cleaned the connection where it hooks into the harness, but I am still getting it.

I assume I need a new sensor. if so, here are a couple of questions

1. Should I expect to change both front sensors?
2. If I am getting new sensors, it almost seems like I'd be better off replacing the entire assebly .. thoughts?
3. This is a 3rd vehicle that barely gets driven ... this next year it will probably log less than 1000 miles. Are there any budget replacement sensors or hub assemblies that you would trust?

Thanks!