Depends....is it a code that is generic to all vehicles? If not you will need a good reader. I have the software from Auto Enginuity. Initial purchaew of it gets you a simple reader that will read only the "Generic Powertrain Codes". You need something specific to a certain vehicle you need to buy the Enhanced Interface for that specific vehicle. This unlocks the software to read ALL systems in a vehicle and perform all sorts of different tests that one of those cheapo readers will never do. Not all engine codes can be read with a cheapo scanner. The cheapo one I have, as well as the three or four that I have tried at a few different NAPA stores would not read my Duramax ECU. Had the check engine light pop on during a road trip once. Had a dirty fuel filter, the cheapo readers would not read that code....nor will it read the code thrown for a leaky/loose fuel cap...