what do these codes mean and how to fix

[youngaudistud]

I have a 2008 audi a4 2.0t quattro 6speed and recetly started making a loud air noise coming from engine alsmost sounds like a blow off valve and it only happens at high rpms around 4000 or 5000 and it is much slower and does not accelerate like it should ,also ive noticed the engine and air filter box and things gets really hot even when i drive it for few minutes. i had revo stage 2 done 3weeks ago which new spark plugs,coil packs and pcv.any suggestions it may be? also i hear i rattling noise when cars idling under the engine cover. I PLUGGED IN OBD TOOL AND THESE CODES CAME UP P0036 CNF, P0172 PND ,P0172 CNF CAME UP TWICE WHAT DO THEY MEAN??

[mec]

Go to obd2 codes .com and look them up

[eyesolution]

Search bar on top of this page will tell you exactly what your looking for.but since your new,
I was the same way, noobie.

Here you go.
http://www.audizine.com/forum/showth...ontrol-Circuit

Rear o2 sensor is the culprit. Buy a new one or slap an angled adapter to it. If you have revo stage two I assume you have a HFC and revo should have a flash for the sensors.

[eyesolution]

Also make sure you have no exhaust leaks.