[Shannon5467]

2009 335i 108xxx miles. I had no3 fuel injector going bad. I swapped the no2 with the no3 and the problem followed. Installed new injector and recoded them both in their locations. New coils, new Bosch plugs. I had a lot of misfiring up to this point. Now the car runs fine at low rpm’s and normal driving. I can feel an occasional misfire. Under heavy load like acceleration or steep hills on the interstate, I get more misfiring and definitely over 4000 rpm’s. The high and low fuel pump sensors are detecting normal pressure. I did notice the Nitrogen Oxide sensor shows faulty power supply. Would this cause these systems of misfiring? I also get the code of 2AAF DME Fuel Pump Plausibility . Any help is appreciated. I’ve owned the car for 2.5 years and drove it 18,000 miles with no issues.

[lowrydr310]

Originally Posted by Shannon5467

2009 335i 108xxx miles. I had no3 fuel injector going bad. I swapped the no2 with the no3 and the problem followed. Installed new injector and recoded them both in their locations. New coils, new Bosch plugs. I had a lot of misfiring up to this point. Now the car runs fine at low rpm’s and normal driving. I can feel an occasional misfire. Under heavy load like acceleration or steep hills on the interstate, I get more misfiring and definitely over 4000 rpm’s. The high and low fuel pump sensors are detecting normal pressure. I did notice the Nitrogen Oxide sensor shows faulty power supply. Would this cause these systems of misfiring? I also get the code of 2AAF DME Fuel Pump Plausibility . Any help is appreciated. I’ve owned the car for 2.5 years and drove it 18,000 miles with no issues.

Have you ever had the walnut blast service performed on the I take valves, or any prior record of it ever being done? It could be as simple as that.

Are you getting misfire codes and a SES light? Or just feeling misfires?

How do you know you're having issues with a faulty power supply error for the oxygen sensors? If that's the case that usually wouldn't cause misfires, but could affect overall performance.

If you have INPA or another BMW specific code reader post the codes that you have.

[Shannon5467]

Originally Posted by lowrydr310

Have you ever had the walnut blast service performed on the I take valves, or any prior record of it ever being done? It could be as simple as that.

Are you getting misfire codes and a SES light? Or just feeling misfires?

How do you know you're having issues with a faulty power supply error for the oxygen sensors? If that's the case that usually wouldn't cause misfires, but could affect overall performance.

If you have INPA or another BMW specific code reader post the codes that you have.

I use an iCarsoft reader for BMWs. I don’t know if the walnut blast has ever been done or even who would do that. I live in St Louis Missouri USA.
When I was looking at the data while driving to work one day, I was checking the fuel pressures. The section on the reader that measures exhaust gas temperature read 0°C and the Nitrogen Oxide sensor was reporting Faulty power supply. The only code showing currently is the 2AAF for the fuel but the pressures are normal or at least close to normal I believe. Also there are random misfire codes that go to different cylinders, no favorites to any one cylinder.

[lowrydr310]

I'd recommend starting with the walnut blast since there's no record of it being done.

This post shows why/how.

It's not difficult to do, but this is one of the few jobs I don't mind just paying to have done. It runs about $300-400 where I am, but that number probably depends on where you live and how many independent shops there are around you. Maybe post in the regional subform to look for a recommendation?