Just fitted a K&N panel filter to my '04 WRX. On starting the car up the Check Engine Light came on and has stayed on. Checked under the bonnet but can't see anything wrong. The car seems to drive just fine but the CEL shows no sign of going away.


Anyone know if this is normal or if not any ideas as to the cause?

Have checked through a number of other threads but haven't found any suggestion that the CEL would be expected to come on after such a basic mod.

 

doesnt sound normal, you havent disconnected the maf sensor have you? (usually though this would cause your car to run badly)

 

Nope not meddled with the MAF sensor at all. Everything that was connected before the filter change has been reconnected after (and double checked)

Just been out and swapped the filter back to the standard paper one and the CEL has gone out so it looks like the "improved" filter is the cause but I don't understand why - would've expected the ECU to cope with the increased airflow.

 

The K&N filters are slightly oiled, Could this oil be contaminating the Hot wire in the Airflow meter ??? Or the K&N is just a red herring & what ever you disturbed putting the K&N in , you have un-disturbed refitting the standard paper one !!!

Dean

 

I've tried wiggling (very scientific!!!) the various connectors in the general area of the airbox to see if anything might have gotten disturbed and be an intermittent connection but nothing seems to cause the CEL to come on/off.

Dunno about the chances of the oil affecting the sensor. Can't rule anything out at this point