A Grand for a tune up??? All of my vehicles are jealous.

IRT to the CEL:

1. it may not be tune up related so you may want to get the code read before you take it in. It could be as simple as cleaning the MAF or as complicated as a leaking head gasket. I get a CEL on my Eclipse once or twice a week. It's either a P0128 or a P0214 (I think ... maybe it's a P0421). Both are related to the engine running too cold ... nothing to worry about in my case (I'm running without a thermostat ... don't ask).

2. you should be OK to drive it with the CEL if it's on steady. That just means that you need to have the diagnostics run soon.

3. if that sucker is flashing though, service is required immediately.

Anyway - hope it's something simple/cheap.