P171 code

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07-18-2007 | 02:55 PM

Krule

Thread Starter

2nd Gear

Joined: Jul 2004

Posts: 986

From:

P171 code

Hey, i'm trying to figure out what the hell code P171 is on my 2001 A4 1.8T. someone please let me know because i need to pass the damn emissions.

07-18-2007 | 03:00 PM

techbod

Joined: Nov 2005

Posts: 12,826

From:

RE: P171 code

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[IMG]local://upfiles/12092/B054BE9C125744FDBD811AAF15D76FF4.jpg[/IMG]

07-18-2007 | 03:09 PM

Krule

Thread Starter

2nd Gear

Joined: Jul 2004

Posts: 986

From:

RE: P171 code

alright, thanks. i will have to check the whole thing i guess. i just got my o2 sensor changed because i tought that was the problem, but the check engine light still keeps coming up

07-18-2007 | 03:21 PM

rccks96

Senior Member

Joined: Oct 2006

Posts: 226

From:

RE: P171 code

Did you put a K&N in recently?

07-18-2007 | 03:24 PM

techbod

Joined: Nov 2005

Posts: 12,826

From:

RE: P171 code

very difficult one here because its the domino effect ( one sensor makes all the other problems ) so I would put it down to air leak/vacuum

07-18-2007 | 07:58 PM

Krule

Thread Starter

2nd Gear

Joined: Jul 2004

Posts: 986

From:

RE: P171 code

no i did not put a K&N filter, i was thinking about it though. but one guy at the shop told me that it could me the whole Cat. thats bad too! i have 84,000 miles on it.

07-19-2007 | 03:26 AM

sdboarder84

1st Gear

Joined: Apr 2007

Posts: 335

From:

RE: P171 code

i would stick to checking the intake for leaks, if it was the cat it would be reading bad on bank 2 not 1.

07-19-2007 | 08:21 AM

CRAZYHAWK

4th Gear

Joined: May 2004

Posts: 4,078

From: Northern NJ USA

RE: P171 code

First check for vacuum leaks.
MAFs are known to go around 85K mi.

07-19-2007 | 11:21 AM

Krule

Thread Starter

2nd Gear

Joined: Jul 2004

Posts: 986

From:

RE: P171 code

i think i found the problem, one of the hoses is cracked and one other thing on the intake is rusted, dunno what to call it hahah but thanks guys hopefully i might get it figured out and fixed