ake11

Car isnt running too good. Its misfiring and loss of power. Also after 4k rpm the check engine light flashes and epc light pops on. ive attached the scan.

any ideas?

5 Faults Found:
004198 - Intake Air Switch-Over Valve (N335)
P1066 - 001 - Short to Plus
Freeze Frame:
Fault Status: 01100001
Fault Priority: 2
Fault Frequency: 2
Reset counter: 255
Mileage: 136637 km
Time Indication: 0
Date: 2015.08.10
Time: 09:58:36

Freeze Frame:
RPM: 3855 /min
Load: 92.9 %
Speed: 55.0 km/h
Temperature: 59.0°C
Temperature: 32.0°C
Absolute Pres.: 1000.0 mbar
Voltage: 13.843 V

000768 - Random/Multiple Cylinder Misfire Detected
P0300 - 008 - - MIL ON
Freeze Frame:
Fault Status: 11101000
Fault Priority: 2
Fault Frequency: 67
Reset counter: 255
Mileage: 136637 km
Time Indication: 0
Date: 2015.08.10
Time: 09:58:37

Freeze Frame:
RPM: 4022 /min
Load: 100.0 %
Speed: 57.0 km/h
Temperature: 102.0°C
Temperature: 66.0°C
Absolute Pres.: 1000.0 mbar
Voltage: 13.843 V

000772 - Cylinder 4
P0304 - 008 - Misfire Detected - MIL ON
Freeze Frame:
Fault Status: 11101000
Fault Priority: 2
Fault Frequency: 67
Reset counter: 255
Mileage: 136637 km
Time Indication: 0
Date: 2015.08.10
Time: 09:58:37

Freeze Frame:
RPM: 4022 /min
Load: 100.0 %
Speed: 57.0 km/h
Temperature: 102.0°C
Temperature: 66.0°C
Absolute Pres.: 1000.0 mbar
Voltage: 13.843 V

004874 - Cylinder Disabling
P130A - 001 - - Intermittent
Freeze Frame:
Fault Status: 00100001
Fault Priority: 2
Fault Frequency: 66
Reset counter: 255
Mileage: 136639 km
Time Indication: 0
Date: 2015.08.10
Time: 11:53:35

Freeze Frame:
RPM: 3406 /min
Load: 87.4 %
Speed: 70.0 km/h
Temperature: 102.0°C
Temperature: 36.0°C
Absolute Pres.: 990.0 mbar
Voltage: 13.589 V

000776 - Cylinder 8
P0308 - 008 - Misfire Detected - MIL ON
Freeze Frame:
Fault Status: 11101000
Fault Priority: 2
Fault Frequency: 2
Reset counter: 255
Mileage: 137749 km
Time Indication: 0
Date: 2015.09.10
Time: 09:08:23

Freeze Frame:
RPM: 1065 /min
Load: 30.2 %
Speed: 0.0 km/h
Temperature: 43.0°C
Temperature: 35.0°C
Absolute Pres.: 990.0 mbar
Voltage: 13.843 V

Readiness: 0000 0001

dseag2

Maybe it would help if you shared the year and model of your Audi?

ake11

sorry, 09' S5

EricBonnes

Did you figure anything out? I have a problem with the air intake switch over valve, also might be able to help with the rest if you did not fix yet

SloopJohnB@mac.com

There are multiple ways to find them from using the Mark 1 Eyeball system to examining cracked hoses, gently pulling them, bleeding propane around hoses and listening/looking for rpm changes or 02 sensor reading (the 02 sensor in FRONT of the cat!), to using a smoke generator on a sealed intake system engine not running to literally smoke out leaks.

There are also other common problems with the 4.2L V8 over time such as a weak coil (move the misfiring coil to another cylinder not misfiring and see if the misfire moves) and even intermittent knock sensor failure (had one intermittent on my 4.2 S6 that was a devil to track down, VCDS wouldn't twig it until I left VCDS on and the fault showed up). There could be combo-valve failures as well leading to excessive lean mixtures.

EricBonnes

It was just a loose wire. But the rest is normally the intake hose. The miss fire happens at higher rpm due to MAF not accounting for the different air intake.