Engine Service Lights and K&N Products
A properly installed K&N product should not cause the Service Light to illuminate. The service light is a warning from the car's computer that something appears abnormal with the car. It does not always mean something is, in fact, wrong with the car and some conditions can cause a false warning. A Service Light can be triggered because the engine is sensing denser air than it expects based on ambient conditions and expected restriction. In that instance, it would trigger a code signifying a Mass Air Flow (MAF) sensor error or lean condition because the Engine Control Module (ECM) is reading air density outside the range it is expecting. These codes can also mean either there is a leak in the air delivery system that needs to be fixed; or the MAF sensor may need cleaning or replacement; or it may be a false warning when in fact nothing is wrong.
In the unlikely event that the Service Light comes on within the first week of installing a K&N High Flow air filter, contact our customer service department and we will help you resolve the issue. If the Service Light comes on after the K&N product has been installed for more than one week and the code is related to the MAF sensor or a "Lean" code, we recommend you visually inspect your air intake path and air filter for leaks. If no holes or cracks can be seen, and you experience no drivability issues it is reasonable to assume you have received a false service light. In that case, have the light reset and it should not recur.
A false reading while rare can be caused by a combination of factors that can momentarily cause the air density to go outside the expected range. Just a moment of an "out-of range" reading may cause the Service Light to illuminate. An example of factors that could cause a false reading is when there is a variation in normal driving conditions such as a vehicle that is under heavy acceleration, going uphill or pulling a trailer, all on a cold day. The three factors in tandem could take air density out of range momentarily and flip the light.
If after resetting the Service light once, it begins to display again, it is unlikely the light has anything to do with the K&N air filter or intake system and we suggest you diagnose the code as discussed below.
The Check Engine light or Service Light means that the vehicle's engine control module (ECM) has detected an error in one or more of the vehicle systems it monitors. There are more than 100 systems monitored by the ECM while the engine is running ranging from the complex such as ignition and exhaust gases to the simple such as lights and an improperly tightened gas cap. Each system monitored is designated a code, and when the Service Light illuminates, a Diagnostic Trouble Code (DTC) is set and stored in the memory of the ECM. Since 1996, these codes cannot be erased by removing power from the vehicle (disconnecting the battery). A scan tool must be used to read the DTC and/or clear them from the ECM's memory. This does not necessarily mean you must take your vehicle to a dealer or independent repair facility. Many auto parts stores are able to read and clear DTC's and turn off the Service Light. Additionally scan tools may be purchased for a modest amount of money and you can read the codes yourself. With the DTC in hand, you can determine whether your vehicle requires repair by calling a dealership repair department or your local auto parts store. If the code is for something simple like an improperly tightened gas cap, you may save yourself a lot of money by getting the code before going to a repair facility. In some instances the Service Light can go off by itself. That can happen because the ECM is pre-programmed by the manufacturer to both turn off the Service Light and clear the DTC from its memory after: (a) a certain number of "drive cycles" have been completed, and (b) the ECM does not monitor the same error again during that certain number of "drive cycles."