Code analysis before car goes in

B6/7 S4/RS4
#1

Ok, so the car has been sitting for over 2 months now and I don’t want to drive it regularly again until I get it sorted. I should finally have some time to put into this hopefully. I plan on taking it in for carbon clean and whatever else that needs to be done with the IM off.
Basically the car runs normal other than on occasion it will kill engine power when I push it at higher RPMs. Various random CEL and EPC will come on and disappear. They come on separately and sometimes together. Below are the codes I pulled today. Again, the car has been barely driven since November and I only put 4000km on it since the summer. I posted similar codes in Komseh’s fuel injector thread, but I figure lets start with this on a new thread. Please guide me into what else needs to be done regarding diagnostics and logs if necessary. Thanks.

Mileage: 112680km-70016mi

Address 01: Engine

3 Faults Found:

008213 - Intake Manifold Flap Position Sensor (Bank 1)
P2015 - 008 - Implausible Signal - Intermittent
Freeze Frame:
Fault Status: 00101000
Fault Priority: 0
Fault Frequency: 7
Reset counter: 255
Mileage: 111606 km
Time Indication: 0
Freeze Frame:
RPM: 1325 /min
Load: 36.5 %
Speed: 0.0 km/h
Temperature: 4.0∞C
Temperature: 9.0∞C
Absolute Pres.: 850.0 mbar
Voltage: 13.208 V

000136 - Fuel Rail/System Pressure
P0088 - 001 - Too High - Intermittent - MIL ON
Freeze Frame:
Fault Status: 10100001
Fault Priority: 0
Fault Frequency: 199
Reset counter: 255
Mileage: 111628 km
Time Indication: 0
Freeze Frame:
RPM: 3630 /min
Load: 22.3 %
Speed: 49.0 km/h
Temperature: 69.0∞C
Temperature: 17.0∞C
Absolute Pres.: 840.0 mbar
Voltage: 13.716 V

006435 - Please Check DTC Memory of ECU Number 2
P1923 - 008 -
Freeze Frame:
Fault Status: 01101000
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 112689 km
Time Indication: 0
Freeze Frame:
RPM: 0 /min
Load: 0.0 %
Speed: 0.0 km/h
Temperature: 2.0∞C
Temperature: 3.0∞C
Absolute Pres.: 840.0 mbar
Voltage: 10.668 V
Readiness: 0000 0000

Address 11: Engine II Labels: 079-910-560-BNS2.lbl

3 Faults Found:

000768 - Random/Multiple Cylinder Misfire Detected
P0300 - 008 - - Intermittent
Freeze Frame:
Fault Status: 00101000
Fault Priority: 0
Fault Frequency: 4
Reset counter: 255
Mileage: 111613 km
Time Indication: 0
Freeze Frame:
RPM: 969 /min
Load: 29.4 %
Speed: 0.0 km/h
Temperature: 57.0∞C
Temperature: 34.0∞C
Absolute Pres.: 840.0 mbar
Voltage: 12.827 V

000775 - Cylinder 7
P0307 - 008 - Misfire Detected - Intermittent
Freeze Frame:
Fault Status: 00101000
Fault Priority: 0
Fault Frequency: 4
Reset counter: 255
Mileage: 111613 km
Time Indication: 0
Freeze Frame:
RPM: 969 /min
Load: 29.4 %
Speed: 0.0 km/h
Temperature: 57.0∞C
Temperature: 34.0∞C
Absolute Pres.: 840.0 mbar
Voltage: 12.827 V

001073 - Warm Up Catalyst; Bank 2
P0431 - 002 - Efficiency Below Threshold - Intermittent
Freeze Frame:
Fault Status: 00100010
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 111958 km
Time Indication: 0
Freeze Frame:
RPM: 2321 /min
Load: 21.2 %
Speed: 31.0 km/h
Temperature: 91.0∞C
Temperature: 14.0∞C
Absolute Pres.: 850.0 mbar
Voltage: 13.589 V

#2

It really helps having the code. It is very wide open. You have a fuel pressure issue that is constant if it was going to happen 2 more times you might have missed it. The fuel pressure is a obvious constant thing.

The missfires look like they are on cold start probably when the car has the SAI system working.

There is deffinitly something wrong with your HPFP or even possibly the LPFP

I wouldnt clear the codes i would grab the LTFT data from both banks

Great idea starting the thread. It is better to have a seperate thread for something like this.

#3

Thanks. Do you feel it is safe to drive the car if there is a potential HPFP issue? I haven’t driven it in a few weeks, so should I put a few hundred km on it before measuring fuel trims.

#4

I wouldn’t risk it with the combination of codes there. Tow it to be safe.

#5

You can clear the codes and check to see if you get more fuel trim codes but its not a question you have an issue with the HPFP or the LPFP for sure.

From the looks of it the fuel code hasnt happened in a few miles. It would be hard to tell you exactly how long ago it was but it happens often.

#6

Ok. I was hoping it was maybe just a fuel pressure sensor. Does that fuel pressure code read only for bank 1 or does the code apply to both banks? I’ll try and get those trims on the weekend.

#7

Its the pressure at the rail so its almost certian that its the LPFP but you always want to check all of them. There is always a possibilty that the sensor is wrong but that would be a different code

#8

hopefully your starter works. Mine was wonky the other morning after 3 days of -20 celsius weather in a row. Just wouldn’t start the car. Took about 3-4 minutes to warm up the solenoid.

#9

Okay, is this the info needed?

Mileage: 112900km-70152mi Repair Order:

            Address 01: Engine  (8E1 910 560 A)

16:16:11 Group 032: Lambda Control (Mixture Adaptation)
-0.6 % Adaptation (Idle) Bank 1 Sensor 1
4.7 % Adaptation (Partial) Bank 1 Sensor 1

            Address 11: Engine II  (8E1 910 560 A)

16:16:59 Group 032: Lambda Control (Mixture Adaptation)

0.8 % Adaptation (Idle) Bank 2 Sensor 1
-1.2 % Adaptation (Partial) Bank 2 Sensor 1

#10

That dosent look very bad. Its not super good but the car isnt screaming stop driving now

#11

So my plan for maintenance goes like this:

carbon clean
flap sensor replacement (both??)
injector clean and flow match

What do the other codes represent:
P0088: is it the LPFP? If so wouldn’t it affect bank 2 as well?
P1923: check DTC memory? what does that even mean?
misfires are likely cold start as mentioned
P0431: catalyst insufficiency, is this the front sensor on driver’s side? Should it be replaced, or is it a failing cat, and I should just get new downpipes? :wink:

#12

I would do a carbon clean with installing intake spacers if you don’t have them already, replace the PCV valve/oil separator, spark plugs, engine air filter, and fuel filter. Along with take your fuel injectors out and ship them out to be cleaned/rebuilt/flow matched.

The intake manifold flap implausible signal codes are likely because of carbon buildup on the flaps causing them to get stuck or the little plastic linkage arms are broken. With the intake manifold off it is really easy to tell if your flaps are covered in carbon or if the linkage arms are broken.

The P0088 fuel rail pressure too high fault code would really cause me to want to send out the injectors to get them cleaned/rebuilt/flow matched. I have seen that code when the fuel injectors are sticking closed on 2.0Ts and FSI V6s. Think about this, the high pressure fuel sensor is at the end of the high pressure fuel rail right. So if the fuel injectors are sticking closed and not spraying the correct amount of fuel in then the fuel pressure can’t bleed off and it will be too high for what the ECUs are looking for.

The P1923 check other ECU dtc memory is just a way of saying to look at the other ECU because it has a fault code too. The RS4s have two engine ECUs because they use a master-slave concept for control of the engine. The ECUs talk to each other a lot and the newer B8 cars will throw that style code for like 10+ modules all because one module on a certain can-bus has a fault code present. Makes for a rather funny customer complaint when they bring in their car and say that there is a Christmas tree of warning lights on the dash all because of one simple fault code, LOL!

The misfire codes are all stored at low engine coolant temps and low engine rpms so that likely is because of carbon buildup.

The P0431 catalyst warm up efficiency code is saying that the pre-cat is not warming up correctly. That likely is because of cold start misfires and the raw fuel being dumped into the cat during cold start up and it can’t burn that stuff so it is failing. Do the other work and see if that code comes back. If it does then get downpipes and a JHM tune to be done with it. Or jump to downpipes and a JHM tune if you want to really enjoy the car while spending a little more money as the rest of the work. Just be sure to get new downpipe studs because they always break.

#13

Great advice there from Jimmy. Lots and lots of storys of bad or failing injectors. So that sould be top of the list with the carbon clean. Who knows how many issues and codes you can be getting from that.

The cat codes can be from bad or stuck injectors as well. Getting JHM dps are always a good options if your looking for more power. The stock RS4 cats are usually pretty strong but if your dumping fuel into them from bad injectors the cats wont last long

#14

You guys are awesome. Thanks for the input.

#15

Always nice to hear the help is helpful. Let us know how all this turns out for you

#16

I’m finally going to take my car in. What is the consensus now on the Hitachi vs OEM injectors? After Oscar’s thread it seems the Hitachis should be fine even though the flow is slightly lower. Is there any evidence to suggest otherwise?

#17

you’re getting new instead of getting them serviced?

#18

Yep. I don’t think its worth it to just service them. It seems a few people have ended up not being able to re-use all of the injectors and then mix old and new. I don’t want to bother with this, and I don’t pull my intake apart every 15,000km to putz with things.

#19

yeah, I’m thinking you use new ones, then sell your old ones after servicing them

if you pay $30/injector and can sell them for $50, it subsidizes the $80/injector for the new ones.

#20

I would think twice before you get the new injectors. There have been more issues with people getting the new injectors then people doing the service. If you do the service you atleast know what you have. If you have one or more injectors you cant use you can just get one or two injectors. You save way more money and you know what the statous of your injectors is when you get them back