What's new
Porsche 911 UK Enthusiasts Online Community Discussion Forum GB

Welcome to the @Porsche911UK website. Register a free account today to become a member! Sign up is quick and easy, then you can view, participate in topics and posts across the site that covers all things Porsche.

Already registered and looking to recovery your account, select 'login in' and then the 'forget your password' option.

RPM Technik is one of the UK’s leading independent Porsche specialists. RPM specialise in all models of Porsche from classic through to current.

P0171 & P0174 Scan Codes

M

Moko

Nurburgring
Joined
12 May 2019
Messages
450
I thought this problem had been solved but scanned again today and getting P0171 and P0174 codes on the scanner.

A couple of months ago I changed the K&N induction kit the car came with when I bought it back to the standard air box and filter. Today I checked and all the jubilee clips look tight and I can't see any obvious leaks. One area I noticed last time was the Allen like bolts holding the MAF sensor was a bit loose so tightened them (does this part need a gasket).

The car definitely felt more sluggish today and didn't want to pull as strongly as the last few weeks.

Is there more I should be checking before I take this any further....ideally if there's a video or list of how to check these things out that would be great.
 
If your scanner can read some actual values then you need to look at the maf voltage ign on but engine not running .. ideally it needs to be at or very close to 1.0 volt .

This will say if its a maf fault .. other items are listed below .. oil cap loose is not uncommon shall we say .
 

Attachments

  • 171_2_1_172.jpg
    171_2_1_172.jpg
    179.2 KB · Views: 3,944
  • 171_1_1_163.jpg
    171_1_1_163.jpg
    236.8 KB · Views: 3,944
I was going to say test the maf but it could be a vacuum leak. Demort will know much more than me but id say faulty maf being both banks or get a smoke test done to check for vacuum leaks would be next. if you disconnect the maf do the codes change at all?
 
I will see if I can get more information out of the scanner and let you know what it says.
 
I don't normally respond to what others post on a thread as i talk to the Op direct and tend to leave it at that ..


All i want to add is that this is a long term fault code .. if you clear the codes then it wont come back for about 4-5 days if it is an actual fault .

Basically the car monitors emission related items over several warm up cycles before it determines there is a fault .

Clear the codes .. unplug the maf and you will only get a maf fault due to the above .. that would logically lead you to assume its a maf sensor fault .

It will not be an accurate test if looking for a repeat of the original codes basically .

A live value of the maf readings will prove it .. 1.0 volt with ign on or approx 18 kg/h with it running .. about 1.35 volts .


No offence meant as this may well be a maf sensor fault but there are other things that can cause it so they all need checking :)
 
Fair point demort. My thinking re removing the maf was if new codes were thrown up or the engine note changed that could lead it to being a different issue as the sensor is obviously giving readings. Didn't know about the cycles etc.
 
Thanks guys as soon as I get a chance will report back.

Just been doing some research in case I do need a new MAF sensor how come there's such a huge difference in prices for what looks basically the same sensor? I've seen about £16 to £198 for them.....is there any recommendations on what to buy if I do need one?
 
Looking at some photos earlier I did notice this on the air box.....should there be something attached to this part?
 

Attachments

  • 521d8599_b4a6_4308_90c9_3e9c7092e991_101.jpeg
    521d8599_b4a6_4308_90c9_3e9c7092e991_101.jpeg
    34.3 KB · Views: 3,867
Not sure what or where that is on the airbox as I don't have one I can remember. have you got a wider shot? If it's the airbox it's job is to get air in and clean it to send it to the engine so not sure it would cause a vacuum leak but could be too much air bypassing or flooding the maf. I will leave this one to Demort as I will just be guessing.
 
Hopefully you can see where it is on the air box from this photo.
 

Attachments

  • 69996c40_69f0_4af4_8305_6d04e3926a64_187.jpeg
    69996c40_69f0_4af4_8305_6d04e3926a64_187.jpeg
    28.1 KB · Views: 3,840
Seeing it now it should be where a clip to hold the maf wire steady sits so I don't think it's a hole all the way through. Found this pic on Google for reference for you.
 

Attachments

  • 996regulator0011210382552_105.jpg
    996regulator0011210382552_105.jpg
    86.2 KB · Views: 3,773
Thanks that makes sense....another thing off the list of worries :D
 
Kbald is perfectly correct .. it's a clip fixing .

I also regret my previous post .. i get frustrated at times .. a simple fault code read out and a look at actual values by an Indy will often point you in the right direction ..

We are not bad guys .. hopefully we all still try to offer a service and as such a £30 read out and and explanation of what we feel is the problem will help .. you can do what you want with that info being it ask us to continue diagnosing or replace the item on an educated guess from someone like me .

At the end of the day that's often how i fix cars .. i can't always prove an item is at fault .. i have to make a judgement , that then is on my head .

Sometimes i don't like what i post .. but i try to give the best info i can .
 
You keep on posting whatever you like ....its a goldmine of information for us amateurs. :)

Hopefully tomorrow I may get sometime to have another look at it.
 
Here's the first scan
 

Attachments

  • 61860d61_61c9_4eb1_99da_700e258ab780_169.jpeg
    61860d61_61c9_4eb1_99da_700e258ab780_169.jpeg
    66.5 KB · Views: 3,622
You must log in or register to reply here.

Similar threads

Alex
Lower control arm/fork refurb
Replies
1
Views
1K
Hugey
Hugey
D
(Recently) noisy 996 turbo ? chain/IMS rattle
Replies
2
Views
1K
IMI A
IMI A
squelch
997 GTS Coolant Leak - Photos attached
2
Replies
19
Views
3K
Luddite
L
M
Codes! Help..
Replies
14
Views
2K
Captain Lockheed
C
B
Female Torx Socket Size?
Replies
9
Views
1K
Blacky
B
H
Split power steering coupling, jubilee "fixable"
Replies
7
Views
859
Quantumjohn
Q
Munzy
997 Turbo Boost Leak - SOLVED!
2
Replies
19
Views
5K
Munzy
Munzy
Porsche Insurance

Latest posts

New Threads

Porsche Model Range

Porsche 911

Porsche 992: 2018- Porsche 992: 2018- Porsche 991: 2011-2019 Porsche 991: 2011-2019 Porsche 997: 2004-2012 Porsche 997: 2004-2012 Porsche 996: 1997-2005 Porsche 996: 1997-2005 Porsche 993: 1993-1998 Porsche 993: 1993-1998 Porsche 964: 1989-1993 Porsche 964: 1989-1993 Porsche Carrera 3.2: 1983-1989 Porsche Carrera 3.2: 1983-1989 Porsche Carrera SC: 1977-1983 Porsche Carrera SC: 1977-1983 Porsche 930 Turbo: 1975-1989 Porsche 930 Turbo: 1975-1989 Porsche Early 911: 1964-1977 Porsche Early 911: 1964-1977

Porsche Hypercars

Porsche 918 Spyder Porsche 918 Spyder Porsche Carrera GT Porsche Carrera GT Porsche GT1 Porsche GT1 Porsche 959 Porsche 959

Other Current Porsche Model

Porsche Taycan : (2019-0%) Porsche Taycan : (2019-0%) Porsche Macan : 2013- Porsche Macan : 2013- Porsche Panamera : 2009- Porsche Panamera : 2009- Porsche Cayman: 2005- Porsche Cayman: 2005- Porsche Cayenne: 2003- Porsche Cayenne: 2003- Porsche Boxster: 1997- Porsche Boxster: 1997-

Porsche Legacy Models

Porsche 928 Porsche 928 Porsche 968 Porsche 968 Porsche 944 Porsche 944 Porsche 924 Porsche 924 Porsche 914 Porsche 914 Porsche 912 Porsche 912 Porsche 904 Porsche 904 Porsche 550 Porsche 550 Porsche 356 Speedster Porsche 356 Speedster Porsche 356 Porsche 356

Forum statistics

Threads
124,545
Messages
1,441,375
Members
48,958
Latest member
Stinkyspanner

porsche insurance porsche parts porsche sales porsche car sales porsche for sale
porsche classic sales porsche tuning porsche sold porsche specialist porsche engine rebuilds porsche driver training porsche car sales porsche exhausts

Community platform by XenForo® © 2010-2024 XenForo Ltd. XenForo theme by xenfocus

www.911uk.com @Porsche911UK THE DEFINITIVE PORSCHE FORUM Copyright © 911UK 2002-2024 All rights reserved.

911uk.com is not associated and is wholly independent of Porsche Automobil Holdings SE, Dr. Ing.h.c.F.Porsche AG, Porsche Cars GB, its subsidiaries and offical Porsche centres. Any word, phrase or graphic that in any way resembles anything to do with the Porsche name or organisation are registered trademarks of Porsche Automobil Holdings SE and Dr. Ing.h.c.F. Porsche AG.

Back
Top