Codes P0171, P0507 + Multiple misfires, High Idle. Frustrated owner here.

[Stretch625]

2007 A4 2.0 TFSI Quattro

P0171, P0507. + Multiple misfires

Idles high but tachometer stays around 800-1000 at times.
Elm Scanner states idle is around 2000 - 3500 RPMs.

Idle can get up to 5000 RPMs when in neutral. Calms down when in Park but fluctuates between 1700 and 800 RPMs.

Morning start up seemingly normal. Heats up cat converters then back down to 730-760 RPMs.

After warming up and during the day, the idle and start up is unpredictable.

Replaced N80, gas cap 0 ring, PCV valve, MAF sensor. Pulled the plugs and coil packs. No oil found on either.

Replaced the cam follower 10,000 miles ago.

Oil cap comes off normal when engine is running.

Sprayed for leaks and listened for air hiss.

Wiggled connections on sensors and elsewhere with no idle change.

Transmission can shift hard at times in D.

Has progressed to not wanting to stay running after start.

Pulled the MAF connection couple of days ago, and now running on default specs.

Cleared the codes a couple of times. Always the same ones come back.

Do these 2.0 TFSI's all have the manifold flaps?

Am I correct in the Idle control module is by the throttle body?

I haven't checked the accordion metal hose from the valve cover and don't know if there is a way to.

Hope I am posting on the right forum?

Any help appreciated. Thanks.

[Sloowww3.oh]

My guess would be either a daily fuse( gotta rule out that) and an idle air controller


Sent from my iPhone using Audizine Forum

[Stretch625]

I have been meaning to check the fuses. what is a daily fuse? The IAC is on the throttle body? removable? Thanks for your input.

[Stretch625]

daily fuse? Never heard of.

[boomtime]

Good troubleshooting steps. I see this tech forum has gotten pretty quiet since ive been gone. It could be as simple as an air or vacuum leak. Remember your not at boosting idle. The Evap and purge are also a possibility, maybe logging evap activation.
2.0TFSI should draw vacuum between -15psi to -19psi on cold startup (high idle) and settle down to between -23psi and -21 psi depending other factors like carbon buildup. Really sounds like a vacuum leak probably behind or at the throttle plate. Also test your TPS sensor. Manifold gasket leak also possible.

[Stretch625]

Thanks for the detailed reply. I ordered and installed, a MAF sensor, 2 days ago, on a hunch, the aftermarket one i installed a year ago, had gone bad, even after spraying it w CRC MAF cleaner a few times, it didn't change the issues. The new one fixed it.

Don't know if I should post a new issue here, but if this catches your experienced eye, are there any oil filter covers (aftermarket, cheap) that you would recommend? I had the oil changed and gave the factory torque specks to the mechanic, [wrench] (would have done it myself if the weather had been decent) but for $25, and my 20-50w European oil + filter, & 0 ring, I supplied, things have gone south and most of it leaked out. I told him make sure the tab on the ring pointed up. Which I m sure he did. The torque was 18 ft lbs. The pan oil bolt was around 22 ft pounds but not leaking from there. I found a magnetic d plug I never got to use from my old A4 3.0. Im thinking the filter case warped, but outside chance that it was cross threaded. Thanks again.

Wanted to add that, I replaced the current filter case. over a year &1/2 ago. When I saw in videos the filter, with a bit of pressure, snaps into place. This one just lets the filter wobble around.