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Discussion Starter #1
Just tripped the code again, I assume 1074 is not far behind.

At this point: New Maf, New hoses, New CCV, 1 Bottle of Lucas injector cleaner.

I had the pros diagnose it and once I fixed the CCV it started running fine. Now it runs fine just tripping the code, so still can't get it inspected...

Ideas?
 

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WOW. That's frustrating...Are you sure you have a BMW air filter? Is the engine missing or doing some sort of hesitation? One or more coils starting to fail kinda crosses my mind but I think they throw another code.
Since you paid for the diagnostic, maybe taking it back they will look into it again?
 

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Just tripped the code again, I assume 1074 is not far behind.

At this point: New Maf, New hoses, New CCV, 1 Bottle of Lucas injector cleaner.

I had the pros diagnose it and once I fixed the CCV it started running fine. Now it runs fine just tripping the code, so still can't get it inspected...

Ideas?
Vacuum leak? The dealer did a smoke test on my 05 looking for a vacuum leak before they determined it was the MAF
 

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Discussion Starter #4
Yep Checked the filter several times. Its clean and certainly BMW branded. Cleaned out the ICV, Throttle body etc when it was all out for the ccv replacment.

About ready to replace the o2 Sensors, at this point there is not much left besides the f'ing block.

I am sure they would recharge me again, but it may be worth it. I just can't think of what the hell else it would be, It now runs great. None of the startup shudder or occasional lag (it has a very very minor shake on cold starts, which I assume is due to just that: cold starts).

Tiny bit of harsh shifting when I am really pushing it hard, again I think those were due to pushing it too soon after startup.
 

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Discussion Starter #5
Vacuum leak? The dealer did a smoke test on my 05 looking for a vacuum leak before they determined it was the MAF
I am starting to wonder if the system is so sensitive that having the butterfly valve on my exhaust unhooked is causing the issue? When the shop used their high dollar tools to check it out last week they showed a code for the butterfly valve non-operable. (it was unplugged).
 

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Discussion Starter #6
Camshaft position sensor?
02 Sensor?
Coils?
Plugs?
Vacuum Leak?

Those are the only things left that seem to be remotely possible.
 

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I lost track - did you replace the Idle Control Valve or the Crankcase Ventilation Valve? Or both?
And have both the flexible intake boot and the plastic intake manifold been ruled out?

Might help to have a more detailed timeline.
Here is my rough idea of the sequence:

1.
non-BMW dealer drives 6 hrs. to deliver the car.
They would be unlikely to do that if they know it keeps throwing a code.
Previous lady-owner was diligent in servicing car at dealer.
No known issues in history of vehicle provided by local BMW dealer?

2.
"Golf-tee mod" done
Some evidence of a cracked hose at the tailpipe end or closer to the engine compartment?

3.
First fill up with gas.
CEL for the first time.
Car still starts and runs fine.
Checks made for vacuum leak.

4.
MAF cleaned.
Idling problems after start up appear for first time.

5.
MAF replaced.
No change.

6.
ICV replaced. No change.
Not seated correctly. Re-seated. Appears to fix problem.
Fix does not seem to last.

7.
Pro. shop diagnoses CVV with estimate of less than $500 (too low?)
CVV done. Appears to fix the problem.

8.
Same CEL back on.
Still runs fine, but code will prevent State inspection pass.
 

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Discussion Starter #8
I lost track - did you replace the Idle Control Valve or the Crankcase Ventilation Valve? Or both?
And have both the flexible intake boot and the plastic intake manifold been ruled out?

Might help to have a more detailed timeline.
Here is my rough idea of the sequence:

1.
non-BMW dealer drives 3 hrs each way. to deliver the car.
They would be unlikely to do that if they know it keeps throwing a code.
Previous lady-owner was diligent in servicing car at dealer.
No known issues in history of vehicle provided by local BMW dealer.

2.
"Golf-tee mod" done
Some evidence of a cracked hose at the tailpipe end or closer to the engine compartment?

3.
First fill up with gas.
CEL for the first time.
Car still starts and runs fine.
Checks made for vacuum leak.

4.
MAF cleaned.
Idling problems after start up appear for first time.

5.
MAF replaced.
No change.

6.
Pro. shop diagnoses CVV with estimate of $485

7.
CCV replaced. Car surges at idle and won't take any throttle without dying.
ICV electrical connection not fully seated. Re-seated. Appears to fix problem.
Car runs perfect

8.
Same CEL back on. (for now it is just P0171, but suspect P0174 is soon to come).
Still runs fine, but code will prevent State inspection pass.
Fixed. (good memory by the way)
 

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So, there was maybe 2 separate problems?

First, the CEL, which had no noticeable effect on engine performance.

Second, the rough running, which did not throw a separate CEL.

Rough running has been fixed, either by the CVV replacement or the ICV cleaning.

The CEL is more difficult to know when it is fixed as you have no immediate feedback.
You have just had to wait and see if it returns.
As it has, wouldn't returning the exhaust flapper to stock be worth trying?
Not that the golf tee mod is known to thrown a code, but in electronic engine management there's always unknowns.
 

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Discussion Starter #10 (Edited)
Logic tells me the rough running was due to the original issue: CCV going out, it just worsened with time.

Engine performance while driving was never affected, it has always had the same get up and go power and no real surges. It was always when stopped at a light or upon startup.

The longer I drove it (running lean) it got worse until one day I was not comfortable with the stress level that the engine was taking. At which point it sat parked until the CCV was replaced.

I will be returning the golf tee mod to normal this afternoon and resetting the CEL. I found a few posts on 7 and 5 series forums where it was simply a bad o2 sensor but it seems that would throw the o2 sensor in the very least at the same time if not before the P0171 code.
 

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Discussion Starter #11
So.... I cleared the P0171 (P0174 never triggered). Day later SES comes on again, no big surprise there. However it was P0420 and P0430 which was odd to me. Is it possible the system is just working out the junk?
 

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Here's what I could find regarding those codes.

http://www.obd-codes.com/p0420

They point it to the O2 sensors or the actual CAT converter. Engine temperature readings ok? Does it take longer to reach Operating temp?
 

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Discussion Starter #14
The dealer I bought it from apparently couldn't get it off their books because it was not registered/inspected/tagged. They drove down, gave me an A4, and have been working on it for 2 days now.
 

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Good to hear they are taking action. Keep us poste on the outcome!
 
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