Jump to content

The RennTech.org community is Member supported!  Please consider an ANNUAL donation to help keep this site operating.
Click here to Donate

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)
Papagut

Very rough idle on start with misfires in one bank only

Recommended Posts

Posted (edited)

Good morning, here is my challenge with my 2004 high mileage Cayenne Turbo: on initial startup, I get a very rough idle that will settle after a minute or two, after the typical start-up cycle, although it will remain a bit rough afterward as well. I ran my codes and came back with these: 

 

P0199 - engine oil sensor (more on that in a moment)

P0021  - cam position timing over advanced or system performance B2

P0431 - catalyst system efficiency below threshold bank 2

Plus misfires on 1, 3, 4 

P0446 - evaporative emission vent control implausible signal

 

I cleared these and ran again for a while, P0021, P0431, and P0199 came back more or less right away. I have had a rough idle in the past, so I checked the various vent lines again + the air oil separator gasket - all look sound, and all have been replaced somewhat recently as well. However, because the codes are all coming from one bank, my thinking is more toward the cam on bank 2 now: maybe the camshaft position sensor is at fault or variable timing solenoid is a bit gummed up. I checked the angles and found bank 2 has a deviation of 3 degrees, not sure if that is significant enough to come into play. Raising the RPM and watching the angles in real time seemed to show the cams responding and adjusting evenly and in step with one another. Also not certain if the O2 sensors on that side are feeding poor information, but not getting any codes indicating that. 

 

Finally, the oil sensor is definitely gone, I have a new one ready to install on my next oil service, which is coming up pretty shortly. This behavior predates the sensor failure, but has been getting worse lately. Plugs are fairly new, coils I checked as well when I did the plugs. The general feeling of vibration I get from the warm engine I am chalking up to aging engine mounts, which have never been replaced to my knowledge. 

 

Any insight you might have to share on what may be the source of my codes would be greatly appreciated.  

 

Thanks, Mark

Edited by Papagut
adding a little detail regarding engine mounts, hoping the edit may also generate more activity

Share this post


Link to post
Share on other sites
    You can remove these ads by becoming a Contributing Member.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.