I have an ongoing P0491 / P0492 issue for... about a year. The current fix attempt is going to be replacing the Air Check Valve. The problem is that I can't find any DIY guide, or even clear location of where the valve is even located.

Does anyone know off hand? I'd love to get this issue behind me so I can move onto the next issue...

 

Have you tried this?

https://www.6speedonline.com/forums/...air-codes.html

 

I can certianly give that a go... would almost be unfortunate if it works seeing as I just bought a replacement valve But fixed is fixed.