Fixed a saggy rear end
Air suspension went on a 2004 Buick Rainier and the backend was on the stops. Instead of trying to diagnose the compressor, sensors, airlines, air bags or controller, I decided to replace the airbags with coil springs. Took me a couple hours and restored the ride height. The included shocks are nice too. With a jack and a couple jack stands, the average DIY mechanic should have no problem.