Mechanics

CAN ANYONE HELP WITH THE CODES P0507 AND P0171???

2006 Audi A4 • 105,000 miles

I have a B4 Audi A4 Quattro. I have a CEL that is giving the codes P0507 and P0171. I have done a little googling on this but haven't found much help. The only thing that seems to be the solution is replacing the PCV (pressure control valve). Symptoms of the car is that at stoplights or when I'm stopped anywhere with the car in neutral and the a/c off, the engine revs up on its own to about 1200-1500 rpm and then drops. It does this cycle repeatedly. When the rpm drops, sometimes it goes so low that it seams like the engine is gonna stall. Also, this does not happen when the a/c is on. Help!
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Hsurquhart85
September 18, 2012.



So you have the 2006 A4 quattro?Which engine?


Saturntech9
Sep 30, 2012.
A4 quattro 2.0T.


Tiny
Cobraphilip
Sep 30, 2012.
There is no iac it uses a throttle servo to adjust idle heres a tip I found for code P0171 let me know what you find.

If you have a B7 (2005.5+) Audi A4 with the 2.0 that has a rough idle and complaint of hesitation along with a lean code and other codes (mine was a misfire, fuel pressure reg code, and idle speed code). Try and take the oil cap off when it is idling. If you cannot or when you do it sucks a rush of air into the engine then you have a PCV issue. These PCV's are crappy and have been revised (so I hear). It is located under the engine cover on the drivers side of the valve cover (see pics). The normal problem is they crap out from the boost pressure and then leak boost into the engine giving you a lower than expected boost pressure. Some times (like this) they can be damaged enough that they give a straight vacuum to the valve cover. Although they shape and design might be vastly different then that of other normal PCV's it is still suppose to perform the same task. There are after market tuning companies that make full metal versions of this unit that retail from 99-150 dollars. The dealership had them for about 60 bucks. Your choice.


Saturntech9
Sep 30, 2012.
Wow lots of suction in the oil cap. I hope to replace the PVC tomorrow. I'll keep you up to date on what I find. Are the pictures located somewhere else?


Tiny
Cobraphilip
Oct 1, 2012.
Heres the pics let me know how it turns out.


Saturntech9
Oct 1, 2012.
Where can the metal aftermarket PVC be purchased from? Do you have a reputable site you trust?
Also, if I went with the dealer, is there a way I can order that part online? Or do I need to call them. I live in a city that does not have an audi dealer.


Tiny
Hsurquhart85
Oct 1, 2012.
Also, how do i know which version of the PCV I have? Im seeing stuff like "n" and "p" versions.
Im currently looking at this website :http://www.urotuning.com/Engine-PCV-System-s/2367.htm

The replacement part looks just like the original. They also have on that comes with a metal "breather tube". Whats the difference b/t all these?


Tiny
Hsurquhart85
Oct 1, 2012.
Audi's are far from my specialty let me doing a little research on this.


Saturntech9
Oct 2, 2012.
Okay, greatly appreciated. Do I NEED to replace the breather tube? Or can I just replace the PCV itself? Obviously as little money spent is better.


Tiny
Hsurquhart85
Oct 3, 2012.
The pcv valve is leaking vacuum into valve cover so I would just replace the pcv.


Saturntech9
Oct 3, 2012.
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