Originally posted by UnIm
All you need to check the codes on you car is a $10 volt/ohms meter. in this case the analog meter is much easier to read.
The diagnostic plug on your car will be located on the right hand side of the fuse box, under the dash. It will be an unplugged connector with 12 pins.The two pins that need to be jumped are the 12 and number 1 pins. with the meter on the VOLTAGE setting and the car in the ON position, the code could be read in short and long bursts of voltage. long bursts signify digits of 10 and short bursts in digits of one.
Or you could just buy a datalogger which you should own anyways if you own any sort of dsm.