|
Engine, Exhaust, Transmission Discuss the FR-S | 86 | BRZ engine, exhaust and drivetrain. |
|
Thread Tools | Search this Thread |
06-04-2017, 04:40 PM | #1 |
Member
Join Date: May 2017
Drives: 2014 Premium Subaru BRZ AT
Location: Saline, MI
Posts: 13
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
|
O2S2 Voltage Always Zero
Hey Everyone first post on here,
I have been having problems with my 2014 BRZ A/T for a while now with rough idle, frequent stalling, running rich. Most frequent codes I am getting are P0172. I have an AEM cold air intake. For awhile I had on an aftermarket UL header, but took it off thinking the O2 sensor positions being in a different position was causing the CEL. After going back to the stock header I still had same problems with CEL and problems listed above. After digging into my OFT deeper I found that the O2S2 Voltage always reads zero and the Wideband AFR always reads >17.0. This made me think either two things. Either I damaged the O2 sensor when changing the headers around. Or I have a loose connection between the signal wire and the ECU (I probed through the signal wire on either sides of the connection and received resistance). Thinking it was most likely a damaged sensor I bought a Walker Downstream O2 sensor (part#: 250-24440) and just replaced it. I turned on the car for a minute thinking I would seem some response to the O2S2 Voltage but it stayed at zero. Do I need to let the car run more and log the data to see if the values change? Should I next look for a loose connection? Could it be anything else? Thank you in advance. |
06-04-2017, 04:48 PM | #2 |
Senior Member
Join Date: Apr 2013
Drives: 2013 FR-S
Location: Seattle
Posts: 806
Thanks: 202
Thanked 321 Times in 199 Posts
Mentioned: 18 Post(s)
Tagged: 1 Thread(s)
|
Check for leaks and clean the MAF sensor. If those don't do it, probably damaged MAF or O2 sensor.
__________________
2013 Whiteout 6AT FR-S | Perrin Inlet Tube + 2.75" CAI | OpenFlash Header | P&L Catback | 4.88 Final Drive | Dialed in OFT 2.0x Stage 2 E85 | 18x8 Enkei Raijin + 225/40 Michelin Pilot Super Sport | 17x7 Stock + 215/45 Michelin X-Ice Xi-2
|
06-04-2017, 04:49 PM | #3 |
Senior Member
Join Date: Aug 2012
Drives: 2013 WR Blue Pearl BRZ Limited 6MT.
Location: Oklahoma City, OK.
Posts: 756
Thanks: 44
Thanked 217 Times in 149 Posts
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
|
It's the aem intake, get rid of it. It's known to make the car run rich. Take off the intake go back with oem and restall the headers and you'll be good
|
The Following User Says Thank You to Dr. BRZ For This Useful Post: | jcw99 (09-14-2022) |
06-04-2017, 05:09 PM | #4 |
Member
Join Date: May 2017
Drives: 2014 Premium Subaru BRZ AT
Location: Saline, MI
Posts: 13
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
|
I have done both of those with checking for leaks and cleaning the MAF sensor. The MAF is reading correctly from the data I've pulled from the OFT. I agree that is my thought too but I just replaced the O2 sensor...
|
06-04-2017, 05:11 PM | #5 |
Member
Join Date: May 2017
Drives: 2014 Premium Subaru BRZ AT
Location: Saline, MI
Posts: 13
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
|
Why would the Wideband AFR read lean (>17.0) if the car is actually running rich (my MPG and nose can tell its running rich) along with the O2S2 voltage reading zero always?
|
06-04-2017, 05:44 PM | #6 | |
Senior Member
Join Date: Oct 2012
Drives: UK GT86
Location: UK
Posts: 3,040
Thanks: 185
Thanked 1,631 Times in 1,112 Posts
Mentioned: 155 Post(s)
Tagged: 1 Thread(s)
|
Quote:
Are you using the MAF box that comes with the AEM? I reckon the intake could be your problem.
__________________
.: Stealth 86 :.
Abbey Motorsport/K47 Tuned Sprintex 210 Supercharger Kodename 47 DJ: Soundcloud / Instagram / Facebook |
|
06-04-2017, 09:21 PM | #7 | |
Member
Join Date: May 2017
Drives: 2014 Premium Subaru BRZ AT
Location: Saline, MI
Posts: 13
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
|
Quote:
|
|
06-05-2017, 03:34 AM | #8 |
Senior Member
Join Date: Oct 2012
Drives: UK GT86
Location: UK
Posts: 3,040
Thanks: 185
Thanked 1,631 Times in 1,112 Posts
Mentioned: 155 Post(s)
Tagged: 1 Thread(s)
|
If you're running the OFT then just re-scale the MAF on your tune. It's an easy and quick fix. Are you running the MAF box that comes with the intake?
__________________
.: Stealth 86 :.
Abbey Motorsport/K47 Tuned Sprintex 210 Supercharger Kodename 47 DJ: Soundcloud / Instagram / Facebook |
06-05-2017, 05:26 AM | #9 |
Banned
Join Date: Dec 2013
Drives: FT86
Location: Australia
Posts: 7,998
Thanks: 1,035
Thanked 4,988 Times in 2,982 Posts
Mentioned: 598 Post(s)
Tagged: 2 Thread(s)
|
+1
That P0172 lean code usually means the ecu is applying over 30% fuel trim correction and the afr is still not correct. Not something you wsnt to leave till September. You might have other issues than the intake , you might have damaged 02 sendor or exhaust leak |
06-05-2017, 10:01 AM | #10 |
Member
Join Date: May 2017
Drives: 2014 Premium Subaru BRZ AT
Location: Saline, MI
Posts: 13
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
|
Okay I will try to do a little research tonight on rescaling the MAF. And yes I am running the AEM MAF box that comes with the intake.
|
06-05-2017, 10:06 AM | #11 | |
Member
Join Date: May 2017
Drives: 2014 Premium Subaru BRZ AT
Location: Saline, MI
Posts: 13
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
|
Quote:
|
|
06-05-2017, 01:14 PM | #12 |
Senior Member
Join Date: Jul 2012
Drives: 2013 Asphalt FR-S Manual
Location: Whitby, ON, Canada
Posts: 6,716
Thanks: 7,875
Thanked 3,353 Times in 2,134 Posts
Mentioned: 99 Post(s)
Tagged: 1 Thread(s)
|
Running too rich will wash the oil off the cylinder walls and can lead to cylinder scoring.
I'll look at what rear O2 reads, but the bigger question is why you're looking at the wrong sensor? Just log AFR (primary O2) against commanded AFR as well as STFT and LTFT.
__________________
Light travels faster than sound, so people may appear to be bright until you hear them speak... flickr |
06-05-2017, 07:10 PM | #13 | |
Banned
Join Date: Dec 2013
Drives: FT86
Location: Australia
Posts: 7,998
Thanks: 1,035
Thanked 4,988 Times in 2,982 Posts
Mentioned: 598 Post(s)
Tagged: 2 Thread(s)
|
Quote:
Yes for some reason it appears the ecu is getting feedback that engine is running lean ie P0172, as its getting feedback that its lean it will be adding the maxium amout of enrichment it can via fuel trims which is over 30% most likely causing a very rich condition. As above poster said you rearly need to diagnose the issue, simply scaling the maf to compensate for another fault , if thats the case, will not solve your problem [ame]https://m.youtube.com/watch?v=5WnM_NsOtd8[/ame] . |
|
06-05-2017, 09:17 PM | #14 | |
Member
Join Date: May 2017
Drives: 2014 Premium Subaru BRZ AT
Location: Saline, MI
Posts: 13
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
|
Quote:
|
|
|
|
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Fuel pump voltage | nelsmar | Engine, Exhaust, Transmission | 9 | 12-01-2013 01:08 PM |
FS: Pivot MegaRaizin Voltage Stabilizer | JPxM0Dz | Canada Classifieds | 0 | 07-29-2013 08:13 PM |
Voltage Fluctuation | Andrew666 | Electronics | Audio | NAV | Infotainment | 5 | 04-21-2013 08:15 PM |
Voltage fluctuations | Andrew666 | AUSTRALIA | 7 | 03-19-2013 09:44 AM |