It all depends on what modifications have been done to your vehicle. If it's stock, there's really no reason for it. However, if you have things like a header or other modifications, or perhaps you've had a code stored in the computer, you'll find that by resetting the computer once in a while, your car will have a chance to relearn all settings and possibly gain better gas mileage and/or more power.
If you do reset it, you'll notice the vehicle will run differently for about 50 miles while it remaps air/fuel mixtures based on all new information from your sensors (O2 sensor, afm air pressure sensor, air temp sensor, etc).
Just don't do what I did! I reset my computer on my truck one day when it was cool and rainy out. I took it around the block and parked it for several days. When I went to drive it again, it was really hot and dry and the truck wouldn't idle at all. I spent about an hour pulling plugs, checking the tps, but nothing helped. After all this, I realized what happened and reset the computer, it ran just fine after that! Bottom line is, drive it for at least 10 or 15 minutes before you park it for a day or two once you reset your computer!!!
Sorry, got a little long winded!
