GuyWithanAudi

Seems to drive ok when the engine has load. When the car is at idle, Cylinders 1-3 will misfire like crazy. I have already ruled out the ICM (Ignition control modules) as I purchased a brand new one and did the swap and it did not switch banks. Is the O2 sensor the culprit? Please help. Thanks in advance.

Also, i hear backfires at times when driving...

evilEE

wow, backfires! Do you have a vag? What codes are you throwing? Did you have any work done to the car lately?
Backfires tell me timing which point to cam-adjusters and associated wiring for bank 1. The plug wires all share a common ground as well for bank 1.

GuyWithanAudi

Below are the DTC's:

5 Faults Found:
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-00 - -
16685 - Cylinder 1: Misfire Detected
P0301 - 35-00 - -
16687 - Cylinder 3: Misfire Detected
P0303 - 35-00 - -
16518 - Oxygen (Lambda) Sensor B1 S1: No Activity
P0134 - 35-00 - -
16686 - Cylinder 2: Misfire Detected
P0302 - 35-00 - -

Was doing some research last night and it is also possible that I have a plugged up Cat? I also heard some backfire when i was driving around yesterday as well. What do you think?

evilEE

Lamda sensor no activity is very strange... sounds electrical. I would ohm out your wiring from the POS for bank 1 to each Coil pack connector to make sure you have good continuity. Shake the wires while you do this.

What did you do the car recently?

evilEE

yeah, plugged cat could do it. Stick a potato in the exhaust for bank 2 and see if it backfires worse.

GuyWithanAudi

I'm thinking the backpressure from the exhaust would make the O2 sensor give false readings maybe? I did not do anything to the car recently other than get new tires. It just up and out of nowhere started misfiring like crazy on my drive home one day.

EuroXS4

Oem plugs?? were they changed???Check plugs and coils. make sure there in good shape and tight.

Peter Badore

Are there any unusual noises from the right cylinder bank. I had a similar problem with a failed bank 1 intake camshaft adjuster that locked the intake camshaft in the advanced position due to a broken adjuster foot. The broken plastic foot was the lower one which was hard to see. If I were you I would remove the bank 1 camshaft cover and check for a damaged intake camshaft adjuster. Also, the DTC for incorrect intake cam timing did not return after I deleted it and I have not been able to determine the parameters for setting the fault code for the camshaft adjusters but they include both speed and a high load.