The Problem:
One of the problems plaguing 993 owners are the infamous clogged Secondary Air-Injection ports. When the ports get clogged, the engine ECU triggers the CEL. Which, apart from being irritating, in most states prevents the car from getting inspection due to "failing" to pass emissions. In actuality, the engine can and does pass emissions testing, but since the CEL is illuminated with the associated trouble codes stored in the ECU, the station must "fail" it. Of course there can be many other reasons the CEL gets triggered - and this Tool assists in pinpointing the issue.
Nasty Surprise #1:
Dealerships and other service providers quote for repair is anywhere between $3000 and $8000. The reason is that the traditional fix often includes doing a full top-end rebuild as well as all the labor to get to the ports for cleaning.
Nasty Surprise #2:
Even after all that expense, the same problem will eventually return.
All in all, very disappointing and quite a hefty price - especially if it was a misdiagnosis!
The Answer:
TurboWerx has developed a very low-cost answer. Our "SAI Diagnostic Tool" can be installed in about 30 minutes. Once the Tool is installed, it will allow continuous monitoring and diagnosis of the oxygen sensors. One of the modes of the diagnostic procedure will eliminate the symptom associated with clogged ports, and the corresponding CEL, thus helping pinpoint the problem. Further, this tool has been tested on many 993s over the last 2 years with 100% continued success. The SAI Diagnostic Tool requires no permanent modification(s) be made to the engine; installation/removal is quick, with no sign it was ever installed. The Tool installs out of the way, under the driver's seat connected to the DME (ECU).
Price: $499
Introductory Pricing: $399.00!
Product Availability: Late Summer, 2009.
Technical
Background
To meet an aggressive CARB requirement, Porsche (and other
manufacturers) added air-injection ports to the cylinder
heads to allow an electric air pump to inject fresh air
into the exhaust stream. This fresh air induction helps the
catalytic converter(s) to come up to operating temperature
a bit quicker. And that's it. The sole purpose of this
elaborate sub-system is to reduce the engines emissions
over a 30-90 second period only at cold-start. This is only
time this system is ever engaged.
It is important to note the US versions of the 993 are
the only cars that have this. None of the European 993s
have this system.
No matter what the miles or condition of the engine, the
ports are slowly getting clogged. For some engines, it
happens as early as 10K miles, others last until 30K or
40K, and a few will last 60-70K+. There will eventually
come a point when the ECU detects enough of a drop in air
flow through the ports to where it finally triggers the CEL
and trouble codes (P0410, P1411). Until now, people and
mechanics had to guess at cause, often times misdiagnosing
the issue. A misdiagnosis of clogged ports can be costly,
since the procedure was to simply "restore" the engine as
close to new as possible. However this doesn't fix the root
cause - it just resets the clock until it happens again.
Some have attempted chemical fixes to clear the passages
with varying degrees of success. Assuming it happens help,
it is still not a permanent fix, and is extremely messy and
toxic. And takes many hours of labor.
One of the reasons that the traditional dealership/service
provider "fix" is so expensive is that they also include
doing a top-end rebuild, whether you need it or not. 993s
have a reputation for having valve guides that prematurely
wear, and this does exacerbate the SAI clogging. However,
it does not mean you must replace them and other associated
parts when the SAI CEL comes on. This "shotgun" approach at
fixing the problem is also a boondoggle for the dealerships
and service providers.
The SAI Diagnostic Tool is 100% effective in helping
pinpoint the SAI issue, and thus avoiding costly
misdiagnosis.