welcome to AZ scottmcguinness172
it could be a number of things that's caused the CEL (check engine light) or MIL (malfuction indicator light) to come on under those conditions, one of the most common causes is a lazy o2 sensor.
to retrieve the error codes from the ecu, you need to make a suzuki special tool, the diagnostic tool numberis #564425681687934...
mine is made from some thin wire & covered in electrical tape & heat shrink.
attached is a word document explaining how to retrieve the error codes. let us know how you get on with the codes, there is a universal o2 sensor that can be used for about $100 or a genuine one at around $330.