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Forum for Engine, Exhaust, Drivetrain, ECU
Liam116
Posts: 8
Joined: Fri Jan 08, 2021 12:16 am
Qashqai Model: Mk.1 Qashqai Facelift - J10b (2010–2013)

Post by Liam116 »

Hi im new to the forum recently purchased a 2010 1.5dci tekna.
I have a problem with the car the mpg is really poor only around 26mpg. The red eml came on a couple weeks ago so i put my obd reader on it and it came up with code P242F which i thought was dpf issue but i got someone out to do a proper diagnostics and the maf sensor come back faulty with high reading of 11 when its meant to be between 2-6 so i replaced it last week but im still getting poor mpg and after another diagnostics by myself the maf reading is again coming back at 11.
As anyone had this issue before and what was the problem?
Thanks

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MikeGC
Posts: 1872
Joined: Tue Feb 07, 2017 11:50 am
Location: Stockport
Qashqai Model: Mk.3 Qashqai - J12 (2021+) New Model

Post by MikeGC »

Sorry to hear your troubles but welcome to the forum.

Being completely non-technical the only thing I would ask (so others might be able to assist you) is:-
The mpg you quote, is that an accurate figure calculated by you on litres used and miles driven (fill the car, drive, refill - calculate) ?
Or the (not as accurate) figure worked out by the car’s computer. If you haven’t reset the computer and it might be inadvertently using years of historic mpg figures to skew the results
March '22 - J12 1.3DIG-T 160 CVT Tekna+ with all wheel drive - Pearl Black
July '19 - J11B 1.3DIG-T 160 DCT Tekna - Vivid Blue
March '17 - Qashqai J11A 1.5dci n-connecta - gunmetal
September '14 - Juke 1.5dci gunmetal ascenta premium (red accent packs)
Liam116
Posts: 8
Joined: Fri Jan 08, 2021 12:16 am
Qashqai Model: Mk.1 Qashqai Facelift - J10b (2010–2013)

Post by Liam116 »

Hello, yes i reset the trip computers after changing maf and compared the reading on torque pro app too and mpg is the same
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calnorth
Posts: 2719
Joined: Mon Feb 11, 2019 2:01 pm
Qashqai Model: Mk.2 Qashqai Facelift - J11b (2017–2021)

Post by calnorth »

Whats the mileage on this car?
Check Engine errors could be a number of things and emissions related is common. Prime responsibility for fuel mixture and combustion sensing is mainly upstream O2 sensor related. MAF is, via the ECU, a slave to 02 sensing along with fuel metering.

I'm not saying it is O2 sensing but at your cars age I'd be looking closely there. Commercial/cheap OBD scanners are likely not useful here.
Mk2 Qashqai Facelift - J11b (2017–and onward)
1.6 Dig-T N-Connecta
Liam116
Posts: 8
Joined: Fri Jan 08, 2021 12:16 am
Qashqai Model: Mk.1 Qashqai Facelift - J10b (2010–2013)

Post by Liam116 »

Its got 118k on it now, may be best trying an auto electrician to pinpoint the issue rather than me keep guessing
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calnorth
Posts: 2719
Joined: Mon Feb 11, 2019 2:01 pm
Qashqai Model: Mk.2 Qashqai Facelift - J11b (2017–2021)

Post by calnorth »

Liam116 wrote: Fri Jan 08, 2021 10:45 am Its got 118k on it now, may be best trying an auto electrician to pinpoint the issue rather than me keep guessing
The problem you have lies in this video in some respects...ability to accurately diagnose and performance monitor in real time (live). Its the kind of procedure that can be difficult for many garages to undertake. Test and measurement being the important thing. When you visit a non dealer its precisely the capability you need to know. And I'm not saying this is the fault you have...its the diagnostic and test follow on capability I'm looking for.

The two types of sensors discussed are basically the same thing. Just that Wideband 02 sensors are common and are more complex. Narrowband sensors are simpler, not often found other than in much older cars going back 10 years and more.

This is the opposite condition to yours...lean mixture. O2 sensors monitor that as well as possible rich conditions. This video is very surprising.

Mk2 Qashqai Facelift - J11b (2017–and onward)
1.6 Dig-T N-Connecta
lewisbryant
Posts: 336
Joined: Sat Feb 23, 2019 7:27 am
Qashqai Model: Mk.3 Qashqai - J12 (2021+) New Model

Post by lewisbryant »

P242f is dpf overloaded.

I suspect you have a split intake pipe near the damper valve which is very common on the euro 5 k9k in the j10. That will be why you have thrown a MAF sensor fault, the reading 11 g/sec is low it should be about 26 to 34g/sec at idle depending on temp of air and atmospheric pressure etc. Do you have boost? Performance low?
Liam116
Posts: 8
Joined: Fri Jan 08, 2021 12:16 am
Qashqai Model: Mk.1 Qashqai Facelift - J10b (2010–2013)

Post by Liam116 »

Ye boost seems fine but i have only had it 2 month, the mpg is just terrible though and when sat in traffic its goes even worse, my mechanic is coming on tuesday to do a service on it, il ask him to check the intake pipe you have mentioned
Liam116
Posts: 8
Joined: Fri Jan 08, 2021 12:16 am
Qashqai Model: Mk.1 Qashqai Facelift - J10b (2010–2013)

Post by Liam116 »

This is some of the reading when idleing, apart from maf do you see anything wrong

8741F309-1FF9-4A69-8D56-2AF25C8B6379.jpeg

lewisbryant
Posts: 336
Joined: Sat Feb 23, 2019 7:27 am
Qashqai Model: Mk.3 Qashqai - J12 (2021+) New Model

Post by lewisbryant »

Is p242f the only fault code when scanned?
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