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
- 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)
Topic is moot at this point. Someone pulled out out a driveway directly in front of me on a city street tonight (on my way to pick up brake pads!) and we collided. The right front corner is a complete mess, so next week the insurance company will have to determine if it is a total loss. See attached photo. The only body panels damaged are the fender and bumper, but I'm certain the whole right side suspension is toast and there is likely significant structural damage.
Thanks! I think I'll try the re-use approach. Separating them while in the calipers seems like a good approach, as they are firmly held In place. If I remove them as a unit, I would likely have to clamp the unit in a vise. I am planning to use Akebono ceramics, as my usual choice, PBR/Axxis are currently not available. The Akebonos appear to have a shim plate clipped to the pads. Does anyone know if that plate is designed to be used in lieu of the Porsche plate on in conjunction with it?
After reviewing online videos, the Boxster brake pad replacement process seemed simple and straightforward, so got new pads and began the task. Something immediately seemed wrong. Whereas in the video, the old pads were easily withdrawn after removing the pins and spring retainers and retracting the pistons, mine wouldn't budge. Looking closely, it looked like my pistons were stuck to the pads (and mighty small pistons they were, strangely). A bit of research revealed, of course, that I was looking at the locating buttons on the shim plates, p/n 996 351 088 02. The videos I watched obviously were of a base Boxster that does not use shim plates. That brings up several questions: 1. What the best method of freeing the plates from the pads, or should I simply remove the calipers and extract the pads and shims as a unit? 2. Are the shims needed (do they do their job of keeping the brakes quiet)?, and if so, can I re-adhere the old shims to the new pads (what adhesive will withstand the heat)? 3. What's the downside of eliminating them entirely and simply using an anti-squeal compound as I have done on all the other cars I've owned? (I know, a Porsche is not any other car). The cheapest I've been able to find the shims for is $40 for a set of four. Few pad sets come with them, evidently, nor do the websites selling the pads have a "you may also need" reference to the shims. I've searched the forums, and strangely, the issue has never been fully addressed on this forum, as far as I can determine. On another forum, some claim that shops routinely omit them, and the claims of their effectiveness is all over the map. One commenter mentioned that he leaves them out so that he can quickly change his pads from street to track. Any and all knowledgeable comments will be much appreciated!
Yep, and if the SAI monitor had still refused to complete, that would have been the logical next step. I'm going to keep an eye out for good prices on the Internet. For the rear sensor that I just bought, the price from my ususal (and often forum recommended) sources was higher than at the local O'Reilly's (Bosch OEM style).
For anyone interested, attached are cold start O2 voltage scans before and after changing sensor B1S2. As is obvious, the blue line is the affected sensor position. Also attached is my smog test results - PASSED!
Nor did I, sorry if it came across that way. I just wondered if there was any monitoring going on that could help further understand the variation we are seeing between vehicles. The first person that told me that completing the SAI monitoring test could be difficult, before I even started this thread, was a local Porsche dealer mechanic.If only we could deconstruct the software. However, as the recent VW fiasco shows, even Porsche may not know every line of code that is in there!
To JFP in response to: "Last week, we had a 2001 base car in the shop for emissions inspection that finally reset the SAI flag after 87 miles of driving over multiple days. And I've seen cars longer that that as well. It doesn't always work itself out with one run cycle." Perhaps it has to do with how responsive the post-cat sensors are. If they are old and slower, it may be that the DME just misses getting the info it needs to set the SAI as "ready". After all, they only have about a minute and a half to detect and signal the air pump's oxygen arriving in the manifolds. Did you do a scan on the O2 voltages during cold start on the vehicle that took 87 miles? After changing my right rear, the scan was dramatically different. All of a sudden, the left rear was (noticibly) the laggard, whereas the right had been before. When the SAI flag is slow, it may not be the miles driven, but the additional cold starts, the final one conveying the DME required info, that leads to the reset. Continous test readiness monitoring while driving, or at least during each subsequent cold start, may either prove or disprove this theory. In any case, the system can't measure the air injection performance EXCEPT during a cold start. Bottom line - my experience only shows that driving after correcting a condition to remove a readiness flag is not ALWAYS necessary. As the saying goes, "your experience may vary".
Yes, that change led to the SAI readiness monitor showing completed. The other pending and full problem codes popping up during the arduous process indicate there may be other latent troubles, in particular there may be an intermittent vacuum leak (reference the pending P1126 code that popped up after a abrupt stop) or a CAT on the way out (reference the P0420 code). But if so, at least they were in abeyance long enough for me to pass smog. I'll clicked the problem solved button.
As mentioned previously, the car has to go through a number of cold starts, full warm up, drive at highway speeds, shut off, and full cool down cycles before it resets. People have promoted specific regimens like the one you mentioned for the 993 from time to time, but I am unaware of a specific one that works consistently on the later cars. My experience belies this. I had all readiness monitors reset except EVAP and SAI. With the help of Ahsai and the O2 voltage readings at cold start-up, it was judged that the slow response of one of the post-cat sensors was the likely culprit. So today, I put in a new Bosch sensor, started the car and ran it through a cold start cycle for 2 and 1/2 minutes sitting in my driveway. I then scanned the DME for smog readiness, and lo and behold, the SAI readiness check was complete and reset! So at least for my 2001 Boxster with a 7.2 DME, running a full drive cycle is NOT necessary to complete the SAI test and remove the flag. BTW, EVAP is still not reset, but that is not necessary to pass smog in California. I immediately drove to my long time smog tester who tested it and it passed- hooray! Thanks so much Ahsai and all the rest of you who have so generously taken the time to read my lengthy posts and offered their expertise, suggestions and insight. This forum is so much better in that regard the some of the others that I also posted on.
Judging by the censoring on my last post, one is not allowed to refer to female dogs on this forum! There goes my reputation even before it was established! Part ordered, will have it by noon tomorrow!
The right rear is a ***** to change because of the Tiptronic plumbing proximity, so no more swapping. I'm off to O'reilly because they can get me a Bosch 15183 (Porsche OEM # 986 606 128 01) for $121 and I'll have it tomorrow. That's $30 more than Amazon, but worth it to get it done sooner. Thanks for all your help and amazingly fast responses, Ahsai!
Just drove an additional 50 miles, no codes nor pending codes. EVAP and SAI still not ready. I clicked on the wrong button and lost the cold start voltage data logs, but I did get screenshots of the approx 2 1/2 minutes after cold start. The air pump shut off at about 1:48 into the log. The first two graphs (image 2 and image 3A) are of the cold start in portrait and Landscape mode. The blue line is the Bank 1 downstream O2 sensor (B1S1), and the red line is the Bank 2 downstream sensor (B2S2). The third graph (image 4) is shows output from about 1 1/2 minutes steady running at approx. 40 mph and 30 seconds or so at idle in drive. There is an obvious difference between the reaction of the Bank 1 downstream O2 sensor and that of Bank 2 upon Air Pump shutoff. The Bank 1 sensor is, of course, the one that threw the pending P0139 code which has not reappeared after being cleared. Is it likely that the reaction of the problematic sensor is preventing SAI readiness? image2.pdfimage3A.pdfimage4.pdf
Yes, and it's the most difficult one to change due to the proximity of the Tiptronic plumbing on that side. I'm going out now to start driving around. I'll capture the start-up O2 voltage data (air pump on and about 30 seconds beyond). My BlueDriver can capture the data and save it as a spreadsheet, but I don't believe it can directly output a graph. It does show it graphically on the screen, so I'll also grab a screenshot. I don't currently have a spreadsheet program on my computer to graph the data.
Latest strange events (and yes, P1146 was a typo, 1126 is correct): This morning I again swapped the upstream O2 sensors to try to determine if I had right bank lean issue or O2 sensor problem. I then went for a drive to the local Porsche dealer, about 20 minutes, while monitoring the sensor voltages . Both sensors seemed to working, similar outputs, no flatlining. When I got to the dealer I checked for codes and lo and behold, the pending P1126 was gone, but there was a pending P0139, bank 1 sensor slow response. Late this evening, I went out to drive around. After ten miles, the P0139 pending code persisted, so I cleared it. I then drove almost 50 more miles, and the pending code did not reappear. My readiness monitors are all set except evap and that pesky SAI. Now that the other problems are in abeyance, I'll try the SAI diagnoses suggested earlier in this discussion using the BlueDriver. I think I may have an intermittent vacuum leak problem on bank 1, so no more jerky driving for now! Thanks once more to everyone for taking the time to make suggestions, and I'll keep you posted.