Anyone had issues with a P0171 code?

[ob_1jr]

Well, I now have almost 51K miles on my car. I had the P0171 popping up for about the past month and a half or so. I took my car in for the fuel rail recall with the CEL on. When I went to pick it up I asked about the code and what they found. Well, the dealership said they didn't find anything, that I didn't have a code. Well I pulled out of the dealer, shifted from first to second and the CEL came on. I took it back to them and they said I had a code for clogged intake (I did download my car and it was there). They cleaned my intake and then told me the car was good to go. I tried to pick it up again. I was sitting just idling and then the CEL came on again. Went back in and told the dealership it was back. They downloaded it again and it had the P0171 just like before. They couldn't reset the code at the time (it was the service advisor doing the download not a tech). So they said it was ok to drive, but I needed to come back at a later date. The english speaking service advisor was out on vacation (I'm in Italy). I told them no problem, I would just download and reset the code myself. So, when I got home this is what I had:

3 Faults Found:
7804 - Position Sensor for Intake Air Regulating Flap
P10A6 00 [032] - Signal too Low
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 81525 km
Date: 2000.00.00
Time: 00:00:00

7811 - Adaptation of Intake Air Regulating Flap
P10A7 00 [096] - Clogged/Dirty
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 81525 km
Date: 2015.06.10
Time: 17:12:39

6208 - Fuel Trim; Bank 1 (Mult)
P1128 00 [236] - System too Lean
MIL ON - Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 2
Mileage: 81526 km
Date: 2015.06.10
Time: 17:16:30

I reset it and then 3 days later it came back with this:

2 Faults Found:
6208 - Fuel Trim; Bank 1 (Mult)
P1128 00 [237] - System too Lean
MIL ON - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 2
Mileage: 81688 km
Date: 2015.06.13
Time: 15:41:15

6212 - Fuel Trim; Bank 2 (Mult)
P1130 00 [100] - System too Lean
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 81688 km
Date: 2015.06.13
Time: 15:41:29

I have an appointment to take my car back next week. Any ideas on what is wrong? I read on alldatadiy and it ranged from fuel filter to maybe a fuel pump. It could be other things, but I didn't go to far into the troubleshooting that it had on there.

[chaos2984]

its not a fuel problem. You would have a code for low fuel pressure if it was fuel problem. And with euro fuel being better than us fuel I would doubt that its a fuel filter issue. But sounds like you might need a t/b adaptation or something is going on with your intake runner flaps and they need adapted. You could have a vacuum leak though also with the lean codes. That could of happened when the car was put back together. Just check all your vacuum hoses as an easy check. It could be intake manifold gaskets also.

[skiptowncat]

swirl flaps in intake manifold may need cleaning or there may be a leak in the mani.

[ob_1jr]

They cleaned the intake flaps and said there was very little build-up. I had the P0171 about a month before I took it in for the recall. In the first download, I don't think they cleared everything out after doing the work. I wish I would have had my laptop with me the first time I went to pick up the car. I will have it next week when I pick it up after taking it in so I can see what exactly is going on if the light comes back. I also want to check and make sure they clear the codes.

Also, I had been running the Roc-Euro intake when this first started happening, but I did put my stock intake back on before taking it in to the dealer. The last time it happened was with the stock intake.

[AudBoost]

Usually that code means a vacuum leak.
I got the same code after I had the fuel rail recall done. Turned out that they did not hook up a vacuum line. I found the line directly behind the throttle body on the backside of the engine (close to the firewall). It was the vacuum line that plugs into the purge valve. check your engine bay for any loose or not connected vacuum lines.

Let me know if you need me to snap a picture of the location where mine was not connected.

[ob_1jr]

I checked all my vacuum lines and they were all on from what I could tell. The dealer will get my car back on tuesday. The service advisor said they had a plan for this time around. I will be checking the codes again before dropping it off to see if it tripped again or not (I didn't clear the codes or the CEL)

[ob_1jr]

Well after the car was at the dealer for 3 days. They confirmed that the codes were set (I already knew they were in the computer because I downloaded again just before taking it to the dealer). Next they ran a few tests. They said that there was no vacuum leak. So, they said they thought that one or a couple of the injectors were partially clogged. So they put some additive in the fuel and drove it for a total of around 75 miles. When I picked up the car they gave me another container of the additive (they said the stuff was good and made in germany). They said to run it through and see how it goes. They also told me to try a different fuel station (I have been using the same one for about 95% of the time since I have owned the car). I guess I will see if it comes back. Only time will tell if it will come back.

[ob_1jr]

Well, no fix. I didn't think it was fixed, but after a week, the P0171 came back with the CEL. Now waiting on what the dealer will say. According to the download, the code happened just after I picked it up from the dealer on the 25th of June. The CEL did not come on until today. The car was idling for about 20 mins while I went in to pick some stuff up and my family was in the car. Hopefully the dealer gets this figured out or I will have to dump the car...and I don't want to do that because I do love the car.

[BoostEasy]

Its a guess but it sounds like the bypass/recirculating valve on the back of the supercharger is outputting a voltage that is too low vs what is expected and/or other problems are causing the ECU to try to adapt to a malfunctioning sensor.

I could be wrong as it's a gamble based on the translation/nomenclature of what "intake air regulating flap" is. It could be the throttle valve but I don't think so as that is usually called something else and it has 2 redundant sensors for measuring throttle angle. It could be the "tumble flaps" that induce tumble into the intake port airflow below the supercharger outlet ports but I can't imagine the engine would actually adapt to cause a lean condition just because of less than ideal tumble into the cylinder intake port and there are 2 (left/right) which the code would have to specify and it is not.

That leaves the bypass/recirc valve as the most likely culprit. I'm either right or wrong. The most efficient way to find out would probably be to:
1) remove and clean the bypass/recirculation valve and see if that helps and also change the actuator for it
2) clear all codes and adaptions in the ECU
3) start checking all the vacuum lines to the tumble flaps, vac lines behind the supercharger and all of the wiring. Take off the intake pipe and remove/clean the throttle body.

It's probably a relatively minor issue and hardly sounds like you need to dump the car.

I hope you get it fixed soon. CEL blues are no fun!

[the4siswickid]

Well, no fix. I didn't think it was fixed, but after a week, the P0171 came back with the CEL. Now waiting on what the dealer will say. According to the download, the code happened just after I picked it up from the dealer on the 25th of June. The CEL did not come on until today. The car was idling for about 20 mins while I went in to pick some stuff up and my family was in the car. Hopefully the dealer gets this figured out or I will have to dump the car...and I don't want to do that because I do love the car.

I have to ask the obvious, but has this dealer called Engineering and/or regional on this? These codes often don't translate well, as you've see from BoostEasy's read and others. The dealers also are at an obvious disadvantage when they try and translate some esoteric issue that isn't completely documented by a TSB or factory service manual. This is why, hiring guys with minimal educations on Audi vehicles, who are post trained ONLY on the equipment used to read the codes and then follow a step by step - essentially a DIY for the shop - manual to do a repair, is just a giant BS mistake. No shop techs really have to think much anymore. They guess when things are esoteric or nonstandard and then, I would say 90% of the time, are already so frustrated, they slap the car back together half assed.

Sorry - rant.

BTW - before I get flamed: I said "minimal education ON AUDI VEHICLES". Not a minimal education overall. I've met many service tech's who've gotten pretty far in school. So this isn't an invitation to slam me.

[teylix]

my tiburon had that code permanently. but it was heavily modified (supercharged, intake (maf sensor), etc.). it usually equates to a vacuum leak as someone mentioned before.

[ob_1jr]

Well the dealer said they did a test to eliminate the intake and vacuum leaks. I have read some of the troubleshooting and some leads to fuel pump or filter. I do have an extended warranty to 75K miles...but I don't know if I want to keep dealing with this problem that long. If I didn't have a Vagcom cable, I would totally be in the dark on this. Yes, I can clear it and it goes away for a while, but I want it resolved so it doesn't happen anymore. Also, I am getting ready to go back to the states and I don't know exactly where I will be. If I have to do emissions testing anywhere, I would hate for the light to pop up when I am getting tested. I am still waiting on what the dealer will say about this. If they don't reply to the e-mail I sent with the download, I will go there on monday to talk to them to see if they can figure something out.

I do not know if they called engineering or regional on this. I am in Italy, so I know they contact Germany when they have issues, but I don't know what they did the last time I took it in. I know the advisor told me they did some research on where to go next. They thought they had it fixed, but from the reading i have done on this code, it is not from driving, but in the start-up sequence or at idle. The dealer thought they had to drive it to make it happen. they said they went on the autostrada to see if they could get it to happen.

honestly when I first saw this code I thought it was from the day I topped the car out at 155 mph...but the code happened about 6 days after I did that. I thought it could have been from the Roc Euro intake, but I have been getting it to come up with the stock intake.

One thing to note. the dealer said that the intake flap for the original code for it being dirty or clogged...there was not that much build-up. I don't know exactly what they did to clean it, but that didn't solve the problem either. I have looked at the vacuum lines and didn't see anything wrong. I guess I need to pull them off one by one and inspect them to see if there is any cracks in them.

[ob_1jr]

Well their reply was to drive it for a couple of days and see if the CEL goes out... I told them that was unacceptable. I need the light out and to stay out. I will be shipping my car within the next month back to the states and having to register it back there. Depending on the state, I may have to go through an inspection, which would check for the CEL being on. Yes, I can reset it myself, but I would hate for it to pop up during the testing/inspection or during the acceptance for the shipper. More to come.

Probably next weekend I will be checking all the vacuum lines myself to see if there is one that has a hole in it or getting too soft. I will end up pulling them off one by one to inspect them. It has to be on a day that I don't plan on driving it first thing though. Nothing like trying to mess with hot vacuum line.

[ob_1jr]

Well the car is back at the dealership. I performed a download of the codes again and the lean code for the right bank occurred 9 more times since the last time I downloaded it and the left bank had one occurrence.

I was talking to the service advisor and he said that the computer should call out another component that is bad, but it doesn't. I asked him how does the car know that there is a lean condition, he didnt know...so I mentioned to him that maybe that sensor is going bad.

Well they told me they would call tech support to see what options they give them. I'm not holding my breath on it being fixed after this trip...I hope it is, but I am not confident that it will be fixed.

[o1turbo30v]

http://wiki.ross-tech.com/wiki/index...5/P0171/000369

[chaos2984]

http://wiki.ross-tech.com/wiki/index...5/P0171/000369

Some of that is wrong. It can't be the fuel pump, lift pump, MAP sensor on ours Those issues would affect both banks the same.

It uses the O2 sensors in each bank to control fueling for each bank independently. It uses the MAP and 02's to control fueling mostly. You need to look at fuel trims with the engine running and compare each bank to each other. You need to see what the short and long terms are doing. If both banks match eachother its going to be something that can affect both banks together. But if your getting the one bank twice as much as the other bank or a x:1 for that one bank then you have something thats going on thats affecting that one bank. It could be a 02 sensor on that bank but it would have to be sticking or something for that to happen. Most of the time its an intake leak. But it can be an injector as well.

[ob_1jr]

I do see the fail on both banks, but it is the right bank more than the left. Also, when reading the alldatadiy troubleshooting, it says that a check valve in the fuel filter, fuel pump, ECM, wiring, fuel injector, O2 sensor, EVAP Canister Purge Regulator Valve, check intake for leaks (dealer says they did this before), and check for vacuum leaks.

I hope that tech support will tell the dealership to check the 02 sensors and such. I haven't heard anything back from the dealership as of yet. I don't expect to hear anything until maybe thursday.

[ob_1jr]

Well, the dealer confirmed the code. They said that it was an O2 code and want to change the injectors. I asked them if that would fix it and they said they needed to start somewhere. I asked why they wouldn't start with 02 sensors? I don't have time for them to just try things. I have to ship my car in 3 weeks. I told them this and asked if they would just change the injectors and O2 sensors at the same time.

The dealer contacted the warranty department in germany and they weren't going to cover it since I was over 50K miles. I told him that was BS because the issue started before 50K and was reported to the dealer and they even had a download from before 50K. After they called Germany again, they said it would be covered. So I will at a minimum get new injectors I guess. I have to wait for the parts to arrive though. Hopefully this will fix the issue.

[ob_1jr]

Well Germany warranty department denied the warranty and the dealership has washed their hands of dealing with my car. they want me to take it back to the states and have a dealer there look at it. I called AoA and they told me that they need all records of what the dealer did here and that Audi would cover the cost of the diagnostics, but not sure they would cover the fix under warranty. So, now I just wait and see. I can see that this car will probably be nickel and diming me to death. Hopefully I find a decent job so I can afford to get rid of this one and probably go back to a GM vehicle as much as I hate to admit it.

[sfali16]

Sad state of affairs - when a dealership with certified techs can't figure out why a fault code is coming on / what can be done to fix it. Did you end up getting rid of your car? I'm currently facing a similar issue but with different fault codes, and my dealership after 4 days of inspecting / driving / testing the car came up with a $4000 quote to replace fuel injectors and O2 sensors, with no assurance that that will fix the problem.
The S4's are great fun to drive, but I would not buy another Audi as I've been disappointed with the ability of their service techs to service their vehicles at least in the Massachusetts dealers.

[ob_1jr]

I did end up getting it fixed by a dealer in St. Louis after I picked the car up from being shipped. It ended up being the PCV. It took them 2 days to fix my car. I didn't have any other codes after that. Funny thing was that when I got the fuel rail recall done in Italy I told them to change the PCV since they would be in there anyway. They didn't have the part in stock and didn't order it when they ordered the rest of the parts. Also, the PCV was fixed under the recall so it didn't cost me anything.

I have since traded in my S4 for a truck, but it wasn't due to any issues I had with my S4.