I've had dual exhaust and a K&N filter on my truck for about 8 months now and haven't noticed much gain in power or MPH. A friend suggested I disconnect the battery for 30 min. He said this would reset the computer which would in turn make it recognize the changes and re-adjust the settings. Any truth to this?

 

Disconnecting the battery will reset the computer. When it relearns it may pic up on your mods some.
A custom tune is the best way to get all your power.

 

I don't think you will gain anything by doing it...but I don't think it would hurt to try. The catback swap has no bearing on engine parameters. It simply allows the exhaust to leave faster. As for the K&N... your motor will only use as much air as needed. You could run with no filter, and its still going to pull the same amount of air. Both of those mods provide very little "real" power gains, so I am not shocked that you don't notice a difference.

 

I think your next step would be to add a tuner.
Those 3 mods work well together. Tuner should give you about 20 to 25 HP.