romite14

Do you need a new seat to change sensor for seat belt, passenger side. Light flashes and airbag light stays on.

ESh

You don't need a new seat. You need to do a scan to see what are the codes and then start from there. I think the sensor in the belt knuckle or the occupant sensor is the problem in this case.

Clutchless

You do need to have Autozone etc scan for codes.
Most of the time the problem is in the latch that receives the seat belt buckle. Try cleaning it with spray brake cleaner etc. They are not hard to replace and used ones are on eBay etc.
It could also be the seat sensor, but code reading will help narrow it down.