Thanks Superdawg. I looked for check-engine-light blinks, too. There weren't any, but I think my year Cherokee doesn't do either the blinking or show the codes on the odometer, and has to be read by a scanner.

Just an update on the suggestion that AutoZone would read my codes for me - I called a few and they all said something about CA not allowing them to read codes for people... wtf. Got no choice but to pay a shop to find and fix whatever they say is wrong.

Well, thanks for the input, everyone.

Jon

99 XJ, 4.5" RE lift, SYE+driveshaft, 31" BFG ATs, Warn rear bumper+tire carrier, JCR front bumper and sliders