[iakonafuji]

Check the O2 sensor on your intake...I installed mine wrong when I installed my injen intake (i know you have stock parts, but im just making a note of this because i had the same problem) and my CEL light would turn on and VSA shut off as well

 

[iakonafuji]

It's not an called an o2 sensors, It's an air flow sensor. But you are right, take a look at it and see if it's fully pluged into the boot.

Check your air filter and make sure that's clean.

Thanks for the correction. O2 sensor is near the Cat, correct?