Update on Engine code issue PO 174
02-05-2016, 12:56 PM
#1
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Update on Engine code issue PO 174
I have spent over $1,400 so far trying to clear this code, (Bank 2 system too lean) 2007 4.2 V8, 95k miles.
the Audi Dealer have replaced an oil separator and some sort of sensor and the light keeps coming back on after a couple of hours.
Next they said the intake manifold bolts needed tightening, then new spark plugs. That's where I told them to stop as they obviously don't have a clue what they are doing...they are now recommending New Fuel Injectors and that the intake manifold may have Carbon build up and will need to be removed and cleaned. an additional $2K
What do you guys think, it seems pretty sad that these diagnostic systems are relatively worthless, here's a code now just throw $$$ at it and eventually we might fix it.
P0174
bank 2 system too lean
confirmed
the Audi Dealer have replaced an oil separator and some sort of sensor and the light keeps coming back on after a couple of hours.
Next they said the intake manifold bolts needed tightening, then new spark plugs. That's where I told them to stop as they obviously don't have a clue what they are doing...they are now recommending New Fuel Injectors and that the intake manifold may have Carbon build up and will need to be removed and cleaned. an additional $2K
What do you guys think, it seems pretty sad that these diagnostic systems are relatively worthless, here's a code now just throw $$$ at it and eventually we might fix it.
P0174
bank 2 system too lean
confirmed
Last edited by shmelvin; 02-05-2016 at 02:52 PM.
02-05-2016, 02:45 PM
#2
AudiWorld Super User
Who is they? Dealership or ? Also diagnostics with a regular OBDII scanner doesn't always give you the best results. VCDS will give you much better results. Also what engine? How many miles?
02-05-2016, 04:36 PM
#4
AudiWorld Senior Member
A quick Google search on the internet came up with the following info:
I hope this info gives you an idea of the probable fault. Here's another lead for you: https://www.2carpros.com/articles/re...-manufacturers
This thread talks about the same PO174 code that an Owner encountered with his '04 A8. He found out it was a vacuum leak that's causing the P0174 DTC.
P0174 OBD-II Trouble Code Technical Description System Too Lean (Bank 2)
What does that mean?
Basically this means that an oxygen sensor in bank 2 detected a lean condition (too much oxygen in the exhaust). On V6/V8/V10 engines, Bank 2 is generally the side of the engine that doesn't have cylinder #1.
Note: This DTC is very similar to P0171, and in fact your vehicle may show both codes at the same time.
Symptoms:
You will more than likely not notice any drivability problems, although there may be symptoms such as a lack of power, detonation (spark knock), and/or a hesitation/surge on acceleration. Causes A code P0174 may mean that one or more of the following has happened: The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters can cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry. There could be a vacuum leak downstream of the MAF sensor.
Possible Solutions Possible solutions include: In the vast majority of cases, simply cleaning the MAF sensor does the trick. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling Inspect all vacuum and PCV hoses, replace if necessary Check for a dirty fuel filter and proper fuel pressure
Read more at: http://www.obd-codes.com/p0174
Copyright OBD-Codes.com
What does that mean?
Basically this means that an oxygen sensor in bank 2 detected a lean condition (too much oxygen in the exhaust). On V6/V8/V10 engines, Bank 2 is generally the side of the engine that doesn't have cylinder #1.
Note: This DTC is very similar to P0171, and in fact your vehicle may show both codes at the same time.
Symptoms:
You will more than likely not notice any drivability problems, although there may be symptoms such as a lack of power, detonation (spark knock), and/or a hesitation/surge on acceleration. Causes A code P0174 may mean that one or more of the following has happened: The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters can cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry. There could be a vacuum leak downstream of the MAF sensor.
Possible Solutions Possible solutions include: In the vast majority of cases, simply cleaning the MAF sensor does the trick. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling Inspect all vacuum and PCV hoses, replace if necessary Check for a dirty fuel filter and proper fuel pressure
Read more at: http://www.obd-codes.com/p0174
Copyright OBD-Codes.com
This thread talks about the same PO174 code that an Owner encountered with his '04 A8. He found out it was a vacuum leak that's causing the P0174 DTC.
Last edited by plat27265; 02-05-2016 at 04:43 PM.
02-09-2016, 11:21 AM
#6
Maybe you can check this if you want to try a cheaper solution.
https://www.audiworld.com/forums/q7-...-4-2l-2861498/
Mine is 128,500 miles now. So that's 16,000 miles after seafoam treatment. Still runs fine, and no CEL or code.
https://www.audiworld.com/forums/q7-...-4-2l-2861498/
Mine is 128,500 miles now. So that's 16,000 miles after seafoam treatment. Still runs fine, and no CEL or code.
02-09-2016, 03:56 PM
#7
AudiWorld Member
By the troubleshooting procedures Audi went down the list to troubleshoot your system. But the 1st thing is the question is that did you replace the fuel filter in the fuel tank? This was my last question from your last request for help. Before replacing any sensors the 1st set is was the fuel filter in the fuel tank was replace? Then reset look for the j623 fuse any good (ECM) then you start with the sensor and intake manifold, and injectors.
MY 2cents. hope you can solve this.
MY 2cents. hope you can solve this.
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