Join Date: Feb 2019
Location: Flat Rock, Michigan
I found this on another site, so I thought I'd repost the information.
1. Disconnect the Negative battery lead.
2. Install the Air Box as per the manufacturer's instructions.
3. Verify that the Negative Battery lead has been disconnected for a minimum of 30 minutes. (I normally give it an hour)
4. Reconnect the Negative Battery lead.
5. Start engine and let idle for a minimum of 15 minutes. (On my Z71 I did 15 minutes with AC on then switched the AC off and let it go another 15 minutes. Then ripped it up and down the street a couple time at Wide Open Throttle.)
What does this do? All newer vehicles are equipped with ECU's that "Learn". Disconnecting the negative battery lead clears the "Learned" programming and returns all ECU settings back to stock. (Depending on the vehicle, this may or may not clear codes). If you have a CEL (Check Engine Light), be sure to clear the code before you begin. The 15 minute idle period in step 5 allows the ECU to re-learn and compensate for the less restrictive CAI. Learning time varies from vehicle to vehicle. I installed the K&N CAI on my 2011 Silverado 5.3 Z71 4x4 and followed the steps outlined above and have not thrown a Lean Code yet.
Also, some vehicles are just angry, if you follow the steps above and find that you have a rough idle after the learning period with the AC on, I would suggest following steps 1,3,&4 again, then for Step 5 let the vehicle idle with the AC on. This will allow the ECU to "Learn" with the additional load on the engine that the AC causes. (Happened on 2 different cars that I installed Air Boxes on).