Jump to content

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)

Iffy ignition coils on my 2004 CS

Recommended Posts

The problem is not that the aftermarket coils on my Cayenne S occasionally fail, it's that they don't fail enough to trip the check engine light so that I can identify which one is the culprit.


A couple of months ago #2 blessedly quit in city traffic only an hour from home, so I isolated the culprit (under the engine mount) and had it changed shortly after we arrived home. It had fixed itself once on the highway and run normally on the retreat to my shop. The spark plug had worked its way loose, even though I had torqued them all to specifications at the time of installation along with the new coils two months earlier.  Up until the point of the code 302 popping, I had gotten into the habit of downshifting in anticipation of a miss whenever I had to slow down in traffic. 


But there's still another coil missing a little bit, occasionally.  


Short of replacing them all with OEM products, does anyone have a way of testing the coils before they get so bad that a code pops up?


Has anyone else noticed a loose spark plug after a bout of missing?

Link to comment
Share on other sites

  • 2 months later...

After a series of coil failures on my '04 CS I bought a set of eight OEM coils from the local dealer.  The car immediately became much more drivable, though the fuel consumption was unchanged.


Amazon.ca is an amazing shopper's resource, but not for Porsche ignition coils.


Now I'm getting P0155, indicating a problem with the heater on the pre-cat oxygen sensor on the left side.  Has anyone found a source of reliable O2 sensors at a good price?  Will one do, or will all four need replacement?

Edited by Rod Croskery
additional info
Link to comment
Share on other sites

Join the conversation

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

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.