On its first trip out after finally passing the MOT test which involved replacing bank 0 lambda sensor to pass the Emissions test, the engine light cam on.
Checked this morning and found the code is P0171.

I found this excellent post on this site

https://www.fullfatrr.com/forum/topic21921...=p0171+4+2


I cannot find any posts on this code on the Supercharged engines.
Has anyone got any experience please, just want to check if there is anything else I should be looking at.

I am assuming it cannot be any shared items like the MAF sensor as bank 1 would show the same code. Is that a sensible assumption?

I have no known performance issues no noticeable misfires, but I will put my diagnostics tool on it this week.

Thanks in advance Range Rover 4.2 Supercharged 2006
Ford Focus EcoBoost 1.5 2017
MG TF 2003

Previous Cars of note
Land Rover Discovery 2
Jaguar Mk2 3.8 - Company car
MG Midget 1974 - Concours

Hi,

I did a search online and found this :- https://www.obd-codes.com/p0171

Good luck

When I had this code a few years ago on my 4.4 petrol I seem to remember it being those pesky PCV hoses turning to blancmange that caused it. An easy thing to check, assuming yours has such hoses.
Afraid I don’t know if this would apply to the s/c engine so it’s possibly a red herring. 2017 Jaguar F Pace 25t Portfolio - still part of the JLR family 😀
2009 3.6 V8 (MY2010) - my first ever diesel! - now also gone
2004 4.4 V8 Petrol Vogue - now gone

Thanks Guys, I have the manual and that gives

Air intake leak between MAF sensor and cylinder head
MAF sensor fault (low intake air flow)
Fuel filter/system restriction
Low fuel pressure
Fuel injector restriction
Exhaust leak (before catalyst)
Evaporative emission system fault

I will add PCV hoses but I can't see how that could cause the problem as its not connected to the air intake system. But if it fixed your issue then maybe it will for me.

So I have the technical info to hand just looking for real time experience from anyone on here. If there is none I will write it up here.

In the meantime I am hoping it will be something simple Range Rover 4.2 Supercharged 2006
Ford Focus EcoBoost 1.5 2017
MG TF 2003

Previous Cars of note
Land Rover Discovery 2
Jaguar Mk2 3.8 - Company car
MG Midget 1974 - Concours

This happened to mine. The fix was a hack but it works. There's flexible urethane epoxy squeezed into the crack then the hose clamps to keep it from spreading again. That could be your leak by the MAF sensor. It was found when a smoke test was done to find a vacuum leak.

Click image to enlarge

Click image to enlarge

Thanks I will check there if need be.
I assume you mean MAP sensor as the MAF is on the Air Filter enclosure.
So its the joint between the Throttle Body intake and the Throttle Body itself.

Did you get code P0174 (bank 2 version of P0171)? As that is a shared part of the intake system I would expect it to affect both banks.

In addition having re-read the manual I now understand how the PCV valve could be the issue so that is definitely on the list. Range Rover 4.2 Supercharged 2006
Ford Focus EcoBoost 1.5 2017
MG TF 2003

Previous Cars of note
Land Rover Discovery 2
Jaguar Mk2 3.8 - Company car
MG Midget 1974 - Concours

Sorry for the delayed response. I don't know the details because it was done at my buddy's shop before I picked it up in October. These are the pictures he sent as he was going through it before I paid him for it and I didn't know much at that point so didn't know what to ask.

I did loads of posts on this same engine about a year maybe slightly longer ago...

It is potentially a massive can of worms...

First very firstly get a smoke test - I had random splits and a little hose off the supercharger elbow, and the oil filler.

Fixed all that still lean, changed both o2 sensors up front and for good measure the rear, slightly better, then I changed the maf. All with genuine parts.

Then did the plugs....

All worked fine for about 6 months then... I got rich faults... ran fine though except a bit of a dirty idle occasionally... changed all the coils and plugs again and so far so good....

Good luck Current stable:
2006 BMW M6
2007 4.2 V8 S/C FF
Gone:
2002 4.4 V8 FF

gravitylover - thanks for your input.

Danwilderspin - Thanks for that, not what I wanted to hear, I was hoping it would be simple, but it never is with these cars.
Did you have only P0171 or did you also have P0174 for the other bank? Range Rover 4.2 Supercharged 2006
Ford Focus EcoBoost 1.5 2017
MG TF 2003

Previous Cars of note
Land Rover Discovery 2
Jaguar Mk2 3.8 - Company car
MG Midget 1974 - Concours

Intermittent sometimes one sometimes both. If I were you get the smoke test first - the rest may be fine and I was jnlocky - I was at 110k if you are significantly higher or lower you are probably fine Current stable:
2006 BMW M6
2007 4.2 V8 S/C FF
Gone:
2002 4.4 V8 FF

Thanks, I will check the garage that did my MOT as they fitted a new O2 sensor on bank 1 under warranty, if they can do a smoke test, then maybe it can all be done under warranty. If not its off to our local indie.

Interesting, your intermittent codes, gives me hope that its probably not injectors.

I'm on 112k so fully expecting these sorts of issues, if the weather was better I would remove everything up to the Throttle Body to check. Range Rover 4.2 Supercharged 2006
Ford Focus EcoBoost 1.5 2017
MG TF 2003

Previous Cars of note
Land Rover Discovery 2
Jaguar Mk2 3.8 - Company car
MG Midget 1974 - Concours

Same sort of mileage as mine so it could well be some of those parts. I also did the In tank fuel filter unit and ran through a can of bg44k injectors seem great on the code reader now.

I would check your maf date too - it’s printed on the top in reverse I believe if it’s original but a new genuine one that fixed the majority of issues after the smoke test Current stable:
2006 BMW M6
2007 4.2 V8 S/C FF
Gone:
2002 4.4 V8 FF

I wasn't aware there was a date on the MAF so I will check that tomorrow.

Was the fuel filter a straight forward job?

Thanks Range Rover 4.2 Supercharged 2006
Ford Focus EcoBoost 1.5 2017
MG TF 2003

Previous Cars of note
Land Rover Discovery 2
Jaguar Mk2 3.8 - Company car
MG Midget 1974 - Concours

Checked the MAF sensor and its dated 06/11/12 so looking at the service records I can guess that it was fitted around 60k miles ago, and was probably fitted by the main dealer looking after the car over a 5 year period.
What I don't know is exactly when it was fitted as I don't have that receipt, and of course I dont know how long it had been on a warehouse shelf before fitting.

Currently its booked in on Wednesday but with the new lockdown rules I don't know if that will go ahead. Range Rover 4.2 Supercharged 2006
Ford Focus EcoBoost 1.5 2017
MG TF 2003

Previous Cars of note
Land Rover Discovery 2
Jaguar Mk2 3.8 - Company car
MG Midget 1974 - Concours

Nope wrong you are falling for my trap ... my maf said 070119 I thought set it’s only a few months old when I got that it couldn’t possibly be that that’s causing all my issues... after spending various amounts on various things i took it to a specialist for something unrelated - wheel bearing as I couldn’t get it off and he said nice car I moaned and he said probably the maf and I said nah it’s only a few months old to which he told me denso date backwards which made sense then when I changed it most of my issues went too.. yours is original my friend - change that puppy and with a denso too

Fuel filter was a bit of a butt to change on mine but I have 7 seats and that was the main problem if you don’t it can easily be done in under and hour. Current stable:
2006 BMW M6
2007 4.2 V8 S/C FF
Gone:
2002 4.4 V8 FF