Audi A4 Random Misfire

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Apexmaster33

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Hey guys,
a few days ago received my Ross Tech cable, and did a Auto scan under engine I am getting random misfire codes, see code, also getting a O2 sensor code. I just replaced the O2 sensor the right side Upstream. however I was told that that code mean I need a new catalytic converter?
secondly what could be causing the random misfire? I drive car daily and the car runs very smooth,and has plenty of power, it does not feel like a random misfire on all 6 cylinders. I have had a misfire on my other car on just 1 cylinder and i felt the engine shake, and lost of power. This is not the case with my Audi. the engine does not shake, idle very smooth, and accelerates as it should .
Address 01: Engine Labels: 06C-909-559-ASN.lbl
Part No SW: 8E0 909 559 L HW: 8E0 909 059
Component: 3.0L V6/5V G 0010
Coding: 0016711
Shop #: WSC 63351 000 00000
VCID: 3E25C0691C6D2407696-5160

8 Faults Found:
17524 - Oxygen (Lambda) Sensor Heating; B1 S1
P1116 - 004 - Open Circuit - MIL ON
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 002 - - Intermittent
16687 - Cylinder 3
P0303 - 002 - Misfire Detected - Intermittent
16690 - Cylinder 6
P0306 - 008 - Misfire Detected - Intermittent
16686 - Cylinder 2
P0302 - 002 - Misfire Detected - Intermittent
16688 - Cylinder 4
P0304 - 008 - Misfire Detected - Intermittent
16689 - Cylinder 5
P0305 - 008 - Misfire Detected - Intermittent
16685 - Cylinder 1
P0301 - 002 - Misfire Detected - Intermittent
Readiness: 0110 1001
 
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Gary

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Check for air leaks first. Have a look at the fuel trim, that will give you an idea if its running lean or rich
 
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Larry Manton

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Apex, you do have a B1 S1 code which could cause a missfire, but not on both banks.

As Gary illuded too would look @ fuel trim and @ what RPM range this happens, is it counting missfires @ idle, or where?

Somebody will want you too post a scan and not just the codes, good luck.


Larimore.
 
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Apexmaster33

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How so I check fuel trim and what rpm its happening? I will post a full scan today on my break. Spark plugs in not sure but the car was serviced 2 years at Audi of Bellevue was last tune up and plugs were done. I have checked air intake system no obvious cracks.
 
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Gary

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How so I check fuel trim and what rpm its happening? I will post a full scan today on my break. Spark plugs in not sure but the car was serviced 2 years at Audi of Bellevue was last tune up and plugs were done. I have checked air intake system no obvious cracks.

The only way to check for air leaks in my opinion is by using a smoke machine.
For a quick look at fuel trim, go in to OBD-II option and use the drop down box and choose what you want to look at.
 
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Jef

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The only way to check for air leaks in my opinion is by using a smoke machine.

I will have to respectfully disagree with that statement. It is good for some quick and dirty testing, but it isn't full proof. We have fielded a lot of false air issues where the callers will tell us they smoke tested and there are no leaks. The correct statement in these cases would be smoke tested, but no leaks found.

IMHO, the best bet is to see what the fuel trim is showing and monitor it while introducing hydrocarbons (brake cleaner or propane) around the engine at idle.
 
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Gary

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I will have to respectfully disagree with that statement. It is good for some quick and dirty testing, but it isn't full proof. We have fielded a lot of false air issues where the callers will tell us they smoke tested and there are no leaks. The correct statement in these cases would be smoke tested, but no leaks found.

IMHO, the best bet is to see what the fuel trim is showing and monitor it while introducing hydrocarbons (brake cleaner or propane) around the engine at idle.

I can only go on my own experience and as yet, I have not failed to find an air leak using the diagnostic smoke machine. Using the brake cleaner method can be difficult to find a tiny pin prick in a hose tucked away out of sight. At least with the smoke machine filling the crankcase with smoke, you can see within a few inches where the leak is. Everyone has their own method. :)
 
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Larry Manton

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Uwe, following along here, and did not know this about 032 and 033 but this was great info. The below 10% is pretty much what I have been taught and the Vag does a great job of letting you look @ the two, thanks.

Larimore.
 
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Jack@European_Parts

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I can only go on my own experience and as yet, I have not failed to find an air leak using the diagnostic smoke machine. Using the brake cleaner method can be difficult to find a tiny pin prick in a hose tucked away out of sight. At least with the smoke machine filling the crankcase with smoke, you can see within a few inches where the leak is. Everyone has their own method. :)

Gary don't rely to much on the smoke machine ......it can be a bad habit and try to do tests with a mighty vac when possible.
Personally If I have a situation where I would consider to use smoke I'd rather use a tracer dye then open up and UV light everything.

UV light NEVER FAILS!
 
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Apexmaster33

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Thank you guys. I will do this over the weekend. However I had something happen to my car last night coming home. On the freeway all the sudden my exhaust got really loud. Sounds like I got a hole or a flange came off . sounds like coming under driver seat so thinking down pipe or cat bolt got loose.
 
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