The gas cap "not tight" has a separate lamp on the dashboard display. This was done to reduce the number of MIL lamp resets needed by the dealerships.

Get a OBD II code reader. They are cheap and the codes are thoroughly explained in many manuals and sources. The codes are standardized. Better than listening to BS from the Dealership saying "there's nothing wrong" and we just reset the code. The code was set for a reason, and YOU should determine if the reason is valid. Things like "misfiring cylinders" mean that a plug is going bad or a coil pack is out of spec.

 

I havn't had any lights or codes going off.

good thing it wasn't serious. Enjoy your new car!

 

Speaking of OBDII readers, what are the things to look for in one? The main difference between the cheap ones the pricier ones is an upgrade capability. Is that worth it?

 

The OBDII reader for the '05-06 Mustang is different from a standard OBDII reader. It requires the OBDII CAN interface which has more pins in the connector and reads more codes than the standard reader. I have one of each, so I've verified this myself.

Try AutoZone. They'll read the codes for you for free and you won't need to invest $150 or more on a reader you may never use again.

UB10