[JFP in PA]

Originally Posted by Frodo

Additional follow-up: Started her up this morning, and (unlike last night, driving to Advanced Auto) the CEL appeared again. It flashed briefly, then became a steady light. Talked to my usual mechanic on the phone, then drove into the shop so he could test it.

The read-out indicated 'misfire, cylinder 1', which he said could be either ignition-related or fuel injector-related. (BTW, when he switched his tester to generic, it---like the tester at Advanced Auto---also read 'no codes'. So, heed Mike Focke's discourse on "CELs in the Boxster" wherein he says: "Be aware that there are codes that the Actron can't read that could be helpful in diagnosing a problem that a Porsche System Tester 2 (PST2) or the later PIWIS can. Dealers have these system tester and some independent mechanics specializing in Porsches have them."

My guy at the indy shop said as long as it's not flashing, it's OK to drive for a short while until I can get her into the shop, but watch for the flashing CEL. He said that it flashes when the misfires are actually occurring, and that's where the serious danger to the catalytic converter exists.

I'm new to all of this. Any comments?

BTW, the only reason I'm driving the Boxster at all at this point is because my other car---a Toyota with 185K miles on it---is getting checked out. I've never before simultaneously had TWO cars that had CELs displayed. It kind of sucks...

As I do not know the specifics of the scanner used, I cannot definitively answer your question. That said, I have never seen a scanner that would not pick up a “P0300” series code (misfires are defined by number, e.g.: a “0304” code indicates that the number 4 cylinder is misfiring, and so on). Even really cheap “read only” scanners can see those.

As for Actron scanners; yes there are codes they cannot see on all cars. These codes represent “restricted access code” areas of the DME such as the airbags, stability management, and often the ABS systems. All OEM’s play this game under the guise that the “protected code” is for “the safety of the owner” because you wouldn’t want an “unqualified technician” working on these areas. In reality, this nonsense is an attempt to exclude independents’ from doing certain repairs, forcing you to go to a dealer. A great example on the 986/987 is the airbag light, which is probably the most accidentally tripped MIL (there are several ways to trip this MIL without there actually being a problem); most dealers charge $75-125 to clear an accidentally tripped airbag light. In reality, it takes about 15 seconds to do; we get $25 to reset them, and often do them for free to regular customers.

As for the PST II/PIWIS; that is another sore point area for independents. The PSTII was a “free standing” system, software that ran on a laptop. Only problems was that the software could be copied, so a lot of PSTII “clones” got into independent’s hands. So Porsche came out with the PIWIS system when the 987 was released, which is a network system that gets its upgrades, etc. over the network rather than on a CD to prevent “illegal cloning”. With the advent of the 987 – 1&2 models, more and more DME functions could no longer be accessed by the older PST II, rendering it obsolete. To be sure, Porsche has offered to “lease” access to the PIWIS system to independent shops, only problem is that the lease starts at about $30K, and that is just for the first year………… and even then the leased systems do not have access to everything the dealers system does, so not many have taken them up on their “offer”.

We use both Actron and Modis systems for about 80-90% of the diagnostics at the shop, and a Durametric Pro system for the rest. I would highly recommend that “backyard enthusiasts” buy a good scanner for their own use as it is one tool that works on any car sold in North America since 1996. While they cannot clear all codes, they can see just about everything, giving you some idea of what is going on. I would suggest getting a unit that is OBD II and CAN bus capable, upgradeable over the internet, and has real-time data capture/PID capability, which allows you do drive around with the unit connected so it can capture random or intermittent codes. Good examples are the better Actron models, which meet these criteria. I would also recommd that you get access to a unit that has data capture and leave it in your car for a while to see if it can see anything other than an occasional misfire. Then, if it is only a misfire, address that issue, which is often a bad plug or a cracked coil pack.