Well my car recently went into limp mode so a friend of mine scanned it for me and this is what it came up with: Fuel trim: Bank 1 : System too lean (sorry, i lost the actual code) I already replaced the o2 censor but the problem came back. My guess is its a faulty MAF. Is there any way to test the MAF? Thanks.

 

Look for a leak in a vacuum line. Not sure about the MAF, unless you have a VAG you can see if you are getting good readings with a VAG COM.

 

I doubt its a vacuum leak, as my boost gauge shows around 20 to 21 inHg during idle, which if i recall correctly is where it should be at.