I've done a few frequent highway drives in the past few days and today the Check VSC light came up all of a sudden while I was cruising.. The car has stock intake and I replaced both air filters a year ago. Any ideas?

 

Clean the MAF with MAF-specific cleaner. How many miles on your current set of spark plugs?

 

I will do so. Hopefully it's nothing major. According to LexusDrivers the current set of spark plugs have only ~25k miles on them. I also ran a health check through techstream and it appears the MAF is ~50 gm/sec

 

The maf reading will vary depending on rpm and throttle position. I've seen my maf reads from 7-216 GM/sec. If your reading too rich the maf is reading high. This could be from turbulence around the maf, try cleaning the maf and inspect the intake for anything that looks out of place.

 

Make sure the "blow-by" tube (the one that leads from the valve cover) is connected to the intake pipe.