Page 1 of 2

B4 BL/BP 2.5L MAF Sensor Location

PostPosted: Thu Dec 10, 2020 6:21 pm
by Callicil
G'day All,

Just wondering if anyone might be able to lead me in the right direction on where to find the location of the MAF sensor on my B4 2005 EJ253 Liberty please? I've lost count of the hours I've spent trying to find any info online and images to see where it should be located, only to find it's not where everyone reckons it should be. From all the info I have read about the model, it should have a MAF sensor, and some even said it has both a MAF and a MAP sensor. I've found what I think is a MAP sensor, but from what I can see online, they sell both MAF and MAP sensors for my car.

If anyone could shed some light on where the MAF sensor could be I would be very greatful. It's not along the air intake pipe as everyone says it should be.

Re: B4 BL/BP 2.5L MAF Sensor Location

PostPosted: Sat Dec 12, 2020 8:51 am
by RX25SE
On all cars, a MAF is located in the intake piping between the air filter and engine (throttle body).

Re: B4 BL/BP 2.5L MAF Sensor Location

PostPosted: Sat Dec 12, 2020 12:28 pm
by BillyCorgi
The MY2005 Factory Service Manual says that the KA country cars (that is Australian model) did not have a MAF.
It used the MAP only concept carried over from the Gen3 Libertys.

Image

Image

Re: B4 BL/BP 2.5L MAF Sensor Location

PostPosted: Sat Dec 12, 2020 6:11 pm
by bigBADbenny
What’s the issue with the car?

See FSM workshop manual link in my signature to get hold of the adm 2005 fsm, adm 2006 should work too.

You’ll find the specific info in the DTC (diagnostic trouble codes, aka CEL’s: check engine light)

And engine related items on H4SO (4 cylinder, single overhead cam) pages.

Re: B4 BL/BP 2.5L MAF Sensor Location

PostPosted: Sun Dec 13, 2020 12:22 pm
by Callicil
Thanks for the info guys. I've actually got it booked in on Monday with my local Subi dealer to have a tech look into it. I believe someone has removed it previously, and have modified the ecu to not look for the MAF (coming from their service guru). I've tried looking in weird places for it, and still nothing. I'll see what they say on Monday as to whether it's been modified in one way or another. But yeah looking at all the manuals I could find, it should be on the intake pipe, but it's unfortunately not there.

I don't have the knowledge of the tools to check codes myself, so I'll leave it in the hands of the pros.

Re: B4 BL/BP 2.5L MAF Sensor Location

PostPosted: Sun Dec 13, 2020 2:08 pm
by BillyCorgi
Callicil wrote:But yeah looking at all the manuals I could find, it should be on the intake pipe, but it's unfortunately not there.


The MY2005 EJ25 KA does not have a MAF.
The ECU in this model is also non-tunable, so the ECU cannot be returned to remove the MAF (if it had one).

Re: B4 BL/BP 2.5L MAF Sensor Location

PostPosted: Sun Dec 13, 2020 4:27 pm
by bigBADbenny
Good luck with dealership diagnostics, I hope it doesnt cost you an exorbitant amount.

If you do pay, just get all the info from them and maybe a repair quote.

I strongly recommend getting the codes scanned for a small fee from eg Super Cheap Auto, note the codes accurately.

Then lookup the diagnostics in the FSM or see a non dealership Subaru specialist or any competent mechanic.

Luckily the engine is of almost agricultural simplicity, meaning health checks are fairly straightforward.

Re: B4 BL/BP 2.5L MAF Sensor Location

PostPosted: Sun Dec 13, 2020 6:53 pm
by bigBADbenny
In fact failing having a scanner that can meaningfully read the ecu (specialist and dealership maybe) the primary diagnostic tools will be a multimeter, scope (maybe), vacuum/pressure gauge (inlet vaccum and fuel pressure, inlet & exhaust pressure/leak test kit, laser thermometer (cat efficiency) and a uv dye and torch kit (fluid leaks).

I’ll be taking my own advice soon for a health check on our 05 2.5i 4eat.
Runs fine, pops the occasional cel which resolves itself soon after.

This is a sign that closed loop afr isn’t up to scratch.
The cel is triggered in low load cruise conditions, eg things affecting the a/f sensor.
In turn this means checking the exhaust, inlet tract, pcv etc.

To begin, I’ll be giving it a thorough upper engine cleaning session using oem uec in the intake, fuel and oil (the latter before an oil change).
Then I’ll some very basic checks like inlet pressure test, check the fuel pump harness for burnt pins.

But not the maf sensor, because the car was never equipped with one from the factory.

Re: B4 BL/BP 2.5L MAF Sensor Location

PostPosted: Tue Dec 15, 2020 3:23 pm
by Callicil
I really appreciate all the info you have all given me. I will definitely be looking into the options posed to me in the replies. I'll see what happens after they've carried out the upper engine clean (Doing it at the same time as the diagnosis).

While writing this I had a call from Subi, and they have informed me that it should have a MAF, but since it doesn't, they are not worried (Which does not put my mind at ease to be honest), but the throttle body is seriously filthy. So I'll see if that makes a difference, and if not, from what I've read, i'll do a vac test next, as the symptoms I have seem to be synonymous with a vac leak / dirty MAF, of which, the latter does not apply to my car.

That is definitely a list I can source through work bigBADbenny, so I will definitely look into it, and also great advice about getting the report in full from them.

BillyCorgi, when I was chatting to the service guru at Subi the other day, I gave him the VIN from my vehicle, and according to his system, he said it was showing that my model should have a MAF sensor, as did NAPA and Tridon through their parts system. But looking at the image you have below, that is the exact layout of mine, so I'm siding with you on the info you posted, which makes a lot more sense than someone modifying the pipe and also the ECU to remove the need for the MAF.


--Update--

I'm too lazy to modify the post (I was meant to post this on Monday, but got sidetracked). They've done a top end clean, and it's running a lot smoother now. Not as much as I would like, but definitely a noticable difference. But again, I thank you guys for your info, as it's something I can work on as I go to try and improve the performance even more, and now that I know the model specifically (VIN did not mention it was the KA variant), I know what components I have to work with.

Re: B4 BL/BP 2.5L MAF Sensor Location

PostPosted: Tue Dec 15, 2020 5:28 pm
by BillyCorgi
Callicil wrote:when I was chatting to the service guru at Subi the other day, I gave him the VIN from my vehicle, and according to his system, he said it was showing that my model should have a MAF sensor, as did NAPA and Tridon through their parts system.


What's your VIN?

Re: B4 BL/BP 2.5L MAF Sensor Location

PostPosted: Wed Dec 16, 2020 9:37 am
by Callicil
G'day Billi,

I'll flick ya a message. Cheers.

Re: B4 BL/BP 2.5L MAF Sensor Location

PostPosted: Wed Dec 16, 2020 12:10 pm
by bigBADbenny
If its even a thing on 2.5i... get your long term fuel trim/s % from the SSM tool if possible.

That’s af learning 1 on a GT.

This value should be within +/-5%.

If not potentially diagnose the good ole air fuel fire triangle starting with the easy stuff, inlet pressure test and looking for exhaust leaks.

Because the 2.5i ecu hasn’t really been open sourced, this isn’t straight forward to do with Btssm or Romraider afaik, either way I’m very interested in your progress.

Its a thing with 2.5i, I suspect inlet manifold gaskets and injector seat seals etc are mostly too hard basket for those who complain they’re unfixable...

Ours is decent but won’t hold cruising speed up really big hills in the country side main/b road situations...

Re: B4 BL/BP 2.5L MAF Sensor Location

PostPosted: Sat Dec 19, 2020 11:59 am
by Callicil
Yeah I know bugger all when it comes to the technical side of the engine management. Mine is not bad for cruising and hills, but at the moment, it struggles in 2nd gear when giving it the beans (1st is a little rough at times too). I haven't done a vac test yet, so I may look at that next as that could be the cause of the sporadic lags in acceleration in 2nd. Also the car had a rough life before i got it, so it may not be worth it running through all these different diagnostics currently. Since having the top end cleaned, it is definitely a noticable difference in the power it uts out.

Re: B4 BL/BP 2.5L MAF Sensor Location

PostPosted: Sat Dec 19, 2020 7:44 pm
by bigBADbenny
What was the top end cleaning procedure?

Gotta UEC my car asap :P

Re: B4 BL/BP 2.5L MAF Sensor Location

PostPosted: Wed Dec 23, 2020 2:28 pm
by Callicil
That is actually a good question my dude.

I'm not too sure exactly what they cleaned in the process, but they did say the throttle body was filthy and that they had cleaned it. And to be honest, apart from the burnt rubber smell I get every now and then, the car is running a shit load better. It does still choke a bit here and there, but, it is a shit load better than before.