Error Code 23
#1
![Question](https://www.scoobynet.com/images/icons/icon5.gif)
Alright guys,
If my dash shows code 23 does it definately mean the MAF is dead/dying (or associated wiring is damaged)? It's on my W reg turbo 2000 btw.
I need more of an experienced opinion before i commit to splashing my hard earned cash towards a new one
Thanks
NB. I have searched but can't find a definitive answer
If my dash shows code 23 does it definately mean the MAF is dead/dying (or associated wiring is damaged)? It's on my W reg turbo 2000 btw.
I need more of an experienced opinion before i commit to splashing my hard earned cash towards a new one
Thanks
NB. I have searched but can't find a definitive answer
![Ponder2](https://www.scoobynet.com/images/smilies/ponder2.gif)
#2
Scooby Regular
iTrader: (3)
Join Date: Aug 2000
Location: 1600cc's of twin scroll fun :)
Posts: 25,565
Likes: 0
Received 2 Likes
on
2 Posts
![Default](https://www.scoobynet.com/images/icons/icon1.gif)
You have an MY00 turbo, code 23 is the maf sensor, if its the original one then its had a good life, cost you just over a ton from a dealer for a new one, well worth it or the other option is a new engine at around 3000 quid, you choose which one you prefer ![Wink](https://www.scoobynet.com/images/smilies/wink.gif)
Tony
![Wink](https://www.scoobynet.com/images/smilies/wink.gif)
Tony
![Big Grin](https://www.scoobynet.com/images/smilies/biggrin.gif)
#3
![Default](https://www.scoobynet.com/images/icons/icon1.gif)
If you've got the error code then either your sensor's totally screwed, or the wiring's duff, or the plug's come unplugged. Likeliest of those is that the sensor's totally screwed (although you should clearly check the plug).
If it's any comfort seeing the CEL is the least worst way for them to fail - as long as it hasn't been dying for months before your ECU noticed. As above just over £100 from your friendly local stealer, a little less from somewhere like AS Performance or Import Car Parts. Part number is 22794AA010.
If it's any comfort seeing the CEL is the least worst way for them to fail - as long as it hasn't been dying for months before your ECU noticed. As above just over £100 from your friendly local stealer, a little less from somewhere like AS Performance or Import Car Parts. Part number is 22794AA010.
Last edited by Splitpin; 20 May 2010 at 07:19 PM.
Trending Topics
#8
Former Sponsor
Join Date: Jul 2005
Location: Wellingborough, Northamptonshire
Posts: 2,859
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://www.scoobynet.com/images/icons/icon1.gif)
You will have that error stored any time the ignition is turned on with the MAF disconnected. But as above, if it doesn't have a green dot/stripe near the top hold of the sensor unit (just the sensor, not the entire housing) then it's an OLD sensor and you should just replace it as a matter of course as a service item. Don't ever buy a used one, there are plenty about and they tend to be dead!
#13
![Default](https://www.scoobynet.com/images/icons/icon1.gif)
If not, as has already been said, the code you've seen reported via the read memory connectors is a historic one - something that has happened at some point in the past between now and the last time the ECU was reset (or the battery disconnected for more than a couple of minutes).
However, code 23 will only trigger if the MAF voltage drops out while the engine is running. Switching on the ignition with the sensor unplugged is not enough to cause the error by itself.
As such, unless you or a previous owner/mechanic has deliberately disconnected the MAF while the engine was on, replacing it still looks the best move. As above you'd be far better off running the black plug + green plug reset routine after replacing it. It'll clear off any learned corrections and will also run an active error check before it gives you the all-clear.
Also, as your current sensor is the green stripe sort, when you take it out (or use a mirror) have a look at the four digit code that should be printed in white ink on the lower part of the mounting flange. The first number's the year of manufacture (i.e. 5= 2005 etc), giving you a more accurate idea how old it is (and therefore how long it's been in there).
#16
![Default](https://www.scoobynet.com/images/icons/icon1.gif)
The fact that it stops running above 4500 also presents the risk that a sensor drop-out at high engine speeds (when you most need it to be accurate) will go completely undetected. Not Subaru's best decision that.
#17
![Default](https://www.scoobynet.com/images/icons/icon1.gif)
The only way to test for certain whether it's reading properly is to test it off the car on a flowbench - blowing a known quantity of air past it and seeing whether the sensor generates the appropriate output.
That's obviously impractical for most people so in practice often the only way to rule in (or out) the airflow meter if your car's suffering a problem is to fit a new one, reset the ECU and see if the problem goes away. If you have access to some datalogging kit you can often spot one going, but you need to know what to look for.
#18
Scooby Regular
iTrader: (6)
Join Date: Jan 2009
Location: on sunny ibiza ocean beach
Posts: 5,594
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://www.scoobynet.com/images/icons/icon1.gif)
It's a problem on a classic too as in most cases they degrade/fail in a manner that doesn't cause a CEL.
The only way to test for certain whether it's reading properly is to test it off the car on a flowbench - blowing a known quantity of air past it and seeing whether the sensor generates the appropriate output.
That's obviously impractical for most people so in practice often the only way to rule in (or out) the airflow meter if your car's suffering a problem is to fit a new one, reset the ECU and see if the problem goes away. If you have access to some datalogging kit you can often spot one going, but you need to know what to look for.
The only way to test for certain whether it's reading properly is to test it off the car on a flowbench - blowing a known quantity of air past it and seeing whether the sensor generates the appropriate output.
That's obviously impractical for most people so in practice often the only way to rule in (or out) the airflow meter if your car's suffering a problem is to fit a new one, reset the ECU and see if the problem goes away. If you have access to some datalogging kit you can often spot one going, but you need to know what to look for.
![Thumb](https://www.scoobynet.com/images/smilies/thumb.gif)
#19
![Default](https://www.scoobynet.com/images/icons/icon1.gif)
Wow, very informative replies!!
I have never seen the 'Engine Check' light flash up on the dash before, only when you plug the two black connectors together.
I did actually unplug the MAF whilst the engine was running as i read on here the engine should change rpm when you unplug it so maybe thats whats caused the error code to pop up when i plug the two black cables together. I never checked the error codes before i unplugged the MAf, doh!!
I guess all i can do is wait until the new MAF shows up and fit it (and do ECU reset), and pray it fixes the problems else that'll be another 100 quid down the shoot.
Will report back tomo.
I have never seen the 'Engine Check' light flash up on the dash before, only when you plug the two black connectors together.
I did actually unplug the MAF whilst the engine was running as i read on here the engine should change rpm when you unplug it so maybe thats whats caused the error code to pop up when i plug the two black cables together. I never checked the error codes before i unplugged the MAf, doh!!
I guess all i can do is wait until the new MAF shows up and fit it (and do ECU reset), and pray it fixes the problems else that'll be another 100 quid down the shoot.
Will report back tomo.
Last edited by prodrive.greeny; 21 May 2010 at 09:36 PM.
#20
![Default](https://www.scoobynet.com/images/icons/icon1.gif)
to pop up when i plug the two black cables together. I never checked the error codes before i unplugged the MAf, doh!!
I guess all i can do is wait until the new MAF shows up and fit it (and do ECU reset), and pray it fixes the problems else that'll be another 100 quid down the shoot.
If nothing changes at all after fitting the new sensor and resetting the ECU, immediately take the new sensor out, back in its box and swap the old one back in. You won't be able to get a refund on the new one but it will be handy to have on your shelf the next time you start scratching your head over the old one.
Have you got the standard induction tract/airbox on, by the way?
Last edited by Splitpin; 21 May 2010 at 10:41 PM.
#21
![Default](https://www.scoobynet.com/images/icons/icon1.gif)
Yes Splitpin, it has standard airbox.
Right then, update.
Got the sensor, fitted it all ok. There were 2 seperate codes on the old and new sensor:
The new one had: C36-700R92 and 9728
The old one i couldn't work out the whole code on it as it had eroded, but i got the second 4 digit code - 6520
Anyway, after the ECU reset i went for a light drive and then pulled over to reconnect the 2 black diagnostic cables. Turned the ignition on, and the 'Engine Check' light flashed constantly so i guess that means there are no fault codes reported??
Then unplugged the black cables and took it for a proper drive creeping right up through the rev range and surprise surprise, the engine coughed/spluttered/hesitated through boost - exactly as before, ****!
So obviously i'm back where i started, 100 quid out of pocket![Cry2](https://www.scoobynet.com/images/smilies/cry2.gif)
Now my suspicions have swung in the direction on the BOV. It's a Bailey DV10 (was fitted by previous owner), i had it refurbished thinking a sticking spring was causing the problems noted so it's now functioning as it should. Next question is then has anyone on here had the same symptoms with a BOV fitted??
HELPPP
Right then, update.
Got the sensor, fitted it all ok. There were 2 seperate codes on the old and new sensor:
The new one had: C36-700R92 and 9728
The old one i couldn't work out the whole code on it as it had eroded, but i got the second 4 digit code - 6520
Anyway, after the ECU reset i went for a light drive and then pulled over to reconnect the 2 black diagnostic cables. Turned the ignition on, and the 'Engine Check' light flashed constantly so i guess that means there are no fault codes reported??
Then unplugged the black cables and took it for a proper drive creeping right up through the rev range and surprise surprise, the engine coughed/spluttered/hesitated through boost - exactly as before, ****!
So obviously i'm back where i started, 100 quid out of pocket
![Cry2](https://www.scoobynet.com/images/smilies/cry2.gif)
Now my suspicions have swung in the direction on the BOV. It's a Bailey DV10 (was fitted by previous owner), i had it refurbished thinking a sticking spring was causing the problems noted so it's now functioning as it should. Next question is then has anyone on here had the same symptoms with a BOV fitted??
HELPPP
![Ponder2](https://www.scoobynet.com/images/smilies/ponder2.gif)
Last edited by prodrive.greeny; 22 May 2010 at 07:34 PM.
#22
![Default](https://www.scoobynet.com/images/icons/icon1.gif)
Anyway, after the ECU reset i went for a light drive and then pulled over to reconnect the 2 black diagnostic cables. Turned the ignition on, and the 'Engine Check' light flashed constantly so i guess that means there are no fault codes reported??
So obviously i'm back where i started, 100 quid out of pocket
![Cry2](https://www.scoobynet.com/images/smilies/cry2.gif)
Now my suspicions have swung in the direction on the BOV.
While you're at it, as the thread's developed you've kinda drip-fed info that it would have been handy to know at the beginning. Giving us a brief rundown of the car's specification/mods, and what you've looked at prior to starting the thread might help us help you. A bit more detailed description of the problem would probably be a good idea too. Does it start to pull fine, and then feel like it's missing, or...?
#23
![Default](https://www.scoobynet.com/images/icons/icon1.gif)
Thanks again.
It's a W reg Turbo 2000, it's definately been remapped but unsure by whom exactly but the former owner said it has the prodrive ECU fitted, it has the small elbow silicone hose running from turbo to intercooler but seems a standard intercooler?? .. along with the wheels and Alcon calipers. Remap wise it definately does feel like the turbo boost has been played with as the turbo does kick in quite aggresively (compared to my friends bugeye). It's also got some kind of large bore exhaust (pretty sure 3") from the downpipe back (2nd cat has been removed).
RE the hesitation issue: It varies from time to time - sometime bad, sometimes almost un-noticable but it's always there. The revs will build smoothly but as the turbo kicks in the boost feels a bit snappy. When it does it badly, the car feels like it's choked but only for a split second, then again and again through the power band. Really hard to describe but feels similar to a car whose engine mount has gone when your powering through the gears. Am i making any sense??
It's a W reg Turbo 2000, it's definately been remapped but unsure by whom exactly but the former owner said it has the prodrive ECU fitted, it has the small elbow silicone hose running from turbo to intercooler but seems a standard intercooler?? .. along with the wheels and Alcon calipers. Remap wise it definately does feel like the turbo boost has been played with as the turbo does kick in quite aggresively (compared to my friends bugeye). It's also got some kind of large bore exhaust (pretty sure 3") from the downpipe back (2nd cat has been removed).
RE the hesitation issue: It varies from time to time - sometime bad, sometimes almost un-noticable but it's always there. The revs will build smoothly but as the turbo kicks in the boost feels a bit snappy. When it does it badly, the car feels like it's choked but only for a split second, then again and again through the power band. Really hard to describe but feels similar to a car whose engine mount has gone when your powering through the gears. Am i making any sense??
#24
![Default](https://www.scoobynet.com/images/icons/icon1.gif)
Thanks again.
It's a W reg Turbo 2000, it's definately been remapped but unsure by whom exactly but the former owner said it has the prodrive ECU fitted, it has the small elbow silicone hose running from turbo to intercooler but seems a standard intercooler?? .. along with the wheels and Alcon calipers.
It's a W reg Turbo 2000, it's definately been remapped but unsure by whom exactly but the former owner said it has the prodrive ECU fitted, it has the small elbow silicone hose running from turbo to intercooler but seems a standard intercooler?? .. along with the wheels and Alcon calipers.
RE the hesitation issue: It varies from time to time - sometime bad, sometimes almost un-noticable but it's always there. The revs will build smoothly but as the turbo kicks in the boost feels a bit snappy. When it does it badly, the car feels like it's choked but only for a split second,
Am i making any sense??
![Wink](https://www.scoobynet.com/images/smilies/wink.gif)
#25
Former Sponsor
Join Date: Jul 2005
Location: Wellingborough, Northamptonshire
Posts: 2,859
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://www.scoobynet.com/images/icons/icon1.gif)
If you crank with the plugs out you will very possible exceed 400rpm, as I have reset ECUs after doing just that and seen plenty of MAF sensor errors over the years.
It's easy to test a MAF sensor if you are running a standard car, and it doesn't require a flow bench. This is the first step of any remap, and just requires that the car is generally otherwise okay and the Lambda sensor is functional. Simply reset the ecu and restart the engine when up to temperature. A good maf will generally result in a closed loop fuel correction within +/- 5% and generally be centered around zero. Failing or failed maf will often be out of that range, in often sit at -10-15% (so reading rich at idle) but soon result in leaner running on load.
Simple answer is get it to someone that can datalog the car and more often or not they can diagnose it either way in 15 minutes for a small charge. In this case it might have saved £100 for a cost of £20.
Current problem sounds like it could be fuel cut, but a lean misfire could also account for it.
It's easy to test a MAF sensor if you are running a standard car, and it doesn't require a flow bench. This is the first step of any remap, and just requires that the car is generally otherwise okay and the Lambda sensor is functional. Simply reset the ecu and restart the engine when up to temperature. A good maf will generally result in a closed loop fuel correction within +/- 5% and generally be centered around zero. Failing or failed maf will often be out of that range, in often sit at -10-15% (so reading rich at idle) but soon result in leaner running on load.
Simple answer is get it to someone that can datalog the car and more often or not they can diagnose it either way in 15 minutes for a small charge. In this case it might have saved £100 for a cost of £20.
Current problem sounds like it could be fuel cut, but a lean misfire could also account for it.
#26
Scooby Regular
iTrader: (6)
Join Date: Jan 2009
Location: on sunny ibiza ocean beach
Posts: 5,594
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://www.scoobynet.com/images/icons/icon1.gif)
If you crank with the plugs out you will very possible exceed 400rpm, as I have reset ECUs after doing just that and seen plenty of MAF sensor errors over the years.
It's easy to test a MAF sensor if you are running a standard car, and it doesn't require a flow bench. This is the first step of any remap, and just requires that the car is generally otherwise okay and the Lambda sensor is functional. Simply reset the ecu and restart the engine when up to temperature. A good maf will generally result in a closed loop fuel correction within +/- 5% and generally be centered around zero. Failing or failed maf will often be out of that range, in often sit at -10-15% (so reading rich at idle) but soon result in leaner running on load.
Simple answer is get it to someone that can datalog the car and more often or not they can diagnose it either way in 15 minutes for a small charge. In this case it might have saved £100 for a cost of £20.
Current problem sounds like it could be fuel cut, but a lean misfire could also account for it.
It's easy to test a MAF sensor if you are running a standard car, and it doesn't require a flow bench. This is the first step of any remap, and just requires that the car is generally otherwise okay and the Lambda sensor is functional. Simply reset the ecu and restart the engine when up to temperature. A good maf will generally result in a closed loop fuel correction within +/- 5% and generally be centered around zero. Failing or failed maf will often be out of that range, in often sit at -10-15% (so reading rich at idle) but soon result in leaner running on load.
Simple answer is get it to someone that can datalog the car and more often or not they can diagnose it either way in 15 minutes for a small charge. In this case it might have saved £100 for a cost of £20.
Current problem sounds like it could be fuel cut, but a lean misfire could also account for it.
what sort offplaces uses datalogs mot testers or rolling road specialists for my bugeye
#27
![Default](https://www.scoobynet.com/images/icons/icon1.gif)
Splitpin, yes it does feel almost like an invisible hand holding the car back for a split second then releasing. Does it sometime as soon as you change up a gear during hard driving.
I've attached a pic of the car, and as you can see - no high level spoiler. I do have a Prodrive performance pack certificate in the service history but the chassis number on it has been tipexed out and mine has been written over the top. I called Prodrive with my chassis number and they confirmed they had no history of it. So I assume at some stage the car has been 'unofficially' fitted with the parts.
![](http://i134.photobucket.com/albums/q117/nofear121/DSCF2581.jpg)
Last edited by prodrive.greeny; 23 May 2010 at 10:09 PM.
#29
![Default](https://www.scoobynet.com/images/icons/icon1.gif)
There are a few causes but more of that in a sec.
![Thumb](https://www.scoobynet.com/images/smilies/thumb.gif)
Right, so now we know what you've got, we know why your say your car feels like the boost has been tweaked - it is running more than a standard one would. As you say, the tippex on the PPP certificate and Prodrive's lack of knowledge sounds like the car has had the bits retrofitted.
As far as your possible misfire/overboost is concerned, one common way to cause it on a PPP car is to fit a decat exhaust, so if you're not 100% sure what's standard and what isn't, try to get some pics of the downpipe and centre section and we should be able to tell you.
It's also possible to get overboost if the boost control pipes are clogged with oil, or if a previous owner has tried to fiddle with the boost pressure by fitting a non-standard air restrictor.
If you are still getting the "problem" on the brand new MAF sensor then it shouldn't be a lean misfire, but that equally doesn't mean it's impossible - a weak fuel pump, for example, is a potential cause.
Does the car have a boost gauge fitted? If it does that'll tell you straight away whether it's overboost or not. In the meantime, have a look at the exhaust and see if the standard catted downpipe is still present. We'll go from there. If in doubt, you've always got the option of having it looked at by a tidy local Subaru specialist or mapper.
#30
![Default](https://www.scoobynet.com/images/icons/icon1.gif)
Thanks again splitpin.
It's got the standard downpipe (with cat) from the turbo and then straight through from there to the backbox which has a pretty sizeable outlet/tailpipe.
I'm guessing in regards to the air restrictor you mean the boost control solenoid? I've searched (and carried out) the 'how to clean solenoid' thread by shooting carb cleaner in it with the green diagnostic cables connected.
It's got the standard downpipe (with cat) from the turbo and then straight through from there to the backbox which has a pretty sizeable outlet/tailpipe.
I'm guessing in regards to the air restrictor you mean the boost control solenoid? I've searched (and carried out) the 'how to clean solenoid' thread by shooting carb cleaner in it with the green diagnostic cables connected.
Last edited by prodrive.greeny; 23 May 2010 at 11:44 PM.