jeffkruse

I have had this car for 3 years now and never had these codes before. I have replaced the Spark Plugs about a year ago. Since they are intermittent, could these because by very low fuel. I have ran it on fumes the past couple of times. If not any suggestions. Sorry I forgot to state that I do not notice any difference in performance.

17536 - Fuel Trim; Bank 1 (Mult)
P1128 - 001 - System too Lean - Intermittent - MIL ON
17538 - Fuel Trim; Bank 2 (Mult)
P1130 - 001 - System too Lean - Intermittent - MIL ON
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 008 - - Intermittent
16685 - Cylinder 1
P0301 - 008 - Misfire Detected - Intermittent
16689 - Cylinder 5
P0305 - 008 - Misfire Detected - Intermittent
16692 - Cylinder 8
P0308 - 008 - Misfire Detected - Intermittent

BASARAB

clear the codes and dont run on fumes. See if codes come back

Jack88

These cars can collect codes randomly. I'd also add swap out the fuel filter if you don't know if it's been done. Running low on gas stresses the fuel pump, done regularly can cause premature pump failure. Not that I think that's the case here. If the codes come back, you'll need to start doing some basic diagnostics to try to narrow down the cause.

MP4.2+6.0

Look for a general vacuum leak. Codes say both sides. Look for stuff like loose clamps, deteriorated hoses, etc. Will be be after MAF on way to motor. Might be something deeper too like injector seals (less likely since codes say both sides), bad intake, etc.

TSHong

+1

Niels3n

I have similar issues on my 2004 4.2L petrol.

It was running fine but went in to a local workshop to have an oil change, and to replace the radiator expansion tank which was leaking.

When I got it back it was running very rough when cold and once warmed up it improves but the engine seems to run poorly when I ease off the throttle. I got a light on the dash and took it back to be checked and have the codes:

P1136 Additive mixture adaption for air (bank1) - System too lean
P1138 Additive mixture adaption for air (bank2) - System too lean
P1128 Multiplicative mixture correction 1 - System too lean
P1130 Multiplicative mixture correction 2 - System too lean
P0139 O2 sensor (bank1, sensor 2) - signal too slow
P0159 O2 sensor (bank2, sensor 2) - signal too slow

My mechanic doesn't look after any other A8's so isn't sure what's causing it. He mentioned that the variable inlet actuator is broken on one side but he's not convinced that this is the cause of the problem.

Any thoughts ?

Thanks,

Niels

MP4.2+6.0

My guess would be yet another vacuum leak scenario. Presumably something that got messed up with the last service. Does air box come out to do a (port injected) 4.2 oil change? If so, look at hoses and clamps between MAF and thottle body as the likely place something didn't go back together correctly.

Niels3n

Many thanks for your help, I know very little about engines so shared the information from this thread with my mechanic and within 15 minutes of checking all hoses and connectors from the MAF to the throttle he found a loose hose connector.

my A8 is now driving smoothly again !