CA Smog and the 993 - OBDII, Readiness and SAI

[Don Plumley]

For the record, here's a summary of how I passed CA Smog with my 96 993.

Background, I brought the car in from Oregon with Cat Bypass pipes. I reconnected the Cat and the post-cat O2 sensors. My OBDII reader said the sensor heating circuits were not working. I replaced the O2 sensors with Bosch Generics (very cool kit). After a coincidental battery disconnect, I cleared the MIL/CEL. No pending or active codes after some driving - yes, that means not SAI problems.

After much searching on drive cycles to set the readiness indicators (non-continuously monitored systems), I did some driving. My friendly smog station did a pre-check of the OBD, and confirmed that my readiness codes were not clear. I drove a lot more. Almost 300 miles under some very unusual conditions (steady speed, coast to less than 20, idle, yada, yada). Still, my reader said, "Not Complete".

Some Rennlisters told me about the Smog Referee. So being the bold type, I found the phone number on the DMV site, called, and set an appointment. I mean, this is a State agency and a human answered the phone after 1 minute, and I had an appointment within 24 hours. She asked why I needed to see a referee, and I indicated that some 96 models have difficulty with the readiness codes. It gets better, the fee is $30 for the inspection plus 8.25 for the certificate. This is about half of the normal price.

The referee is at the local Junior College. He was non-plussed that I didn't have a failed smog test result. Procedurally, I should have paid for an inspection, failed it due to no readiness codes, then asked for the appointment. Well, I was there anyway and was pretty clear on the problem - I offered to take it somewhere and fail the test - but he decided to test the car.

And test it they did. I mean an hour of looking, poking, prodding. Somebody owes my car dinner.

Result: Smog Certificate. The emission tests are very, very clean. Reading the cert, it says Functional Check: Fail; Air Injection (that's that dreaded SAI code): Fail. But, in the fine print it says, "The vehicle failed the MIL/CEL test due to failure to successfully complete all OBD self tests".

The referee says, "I pass the car because of the ODB problem not setting the readiness codes." He was miffed at the BAR for not having this in their database. IF it ever gets in the CA BAR database, then when you go to a smog center, they'll have a note that the OBD readiness codes may not pass, and it's okay.

Implications: I'm not messing around with the drive cycle nonsense every two years (assuming I had codes to reset or a battery disconnect). I'll simply go fail a test, then get an appointment for the referee.

Hypothetical extrapolation: It seems to me if you have a true SAI problem, and as long as you don't have a pending DTC stored, you could (and I'm not advocating anyone here break the law) theoretically speaking, disconnect your battery to clear all codes - go fail a smog test, then go see a referee (don't drive more than 100 miles or do another disconnect) and get your cert. YMMV.

Don

[AFJuvat]

I'm posting this as a sticky for our California members to read.

Thanks for the info Don.

AFJ
Moderator.

[syncroid]

This problem that you describe is not only inherent in 96 993s. 96-98s have the problem as well. We get cars coming in to our shop all the time that have not run the readiness codes. Porsche has a procedure that "if" followed to the "T" will set the readiness codes. Its a major pain in the a$$ to get them to trip. We have been telling our customers to do just as you did. GO to the referee. It is a known problem.

[Jascha]

I encountered the OBD Readiness Fail problem as well for the first time while having my '96 993 inspected (in PA). I took it for a short drive hoping to ‘recycle’ the PCM but it did not stick…

Is it likely that a longer ‘drive cycle’ will do it....?

BTW, I recently changed one of the O2 sensors and reset the DTC (code P0131; low voltage in bank 1 sensor 1)...?


Thanks
Jascha

[Don Plumley]

Jascha - Once you reset the DTC (after the sensor replacement), the readiness codes get reset to zero. Loren's site has a nice summary of the drive cycle functions required to trip the readiness indicators.

The drive cycle is not reset by length of time driving - the car must pass through a sequence of events to trip the various indicators. Long periods of time (5 min) idling seems to be one of the keys.

I ran out of patience trying to set the readiness indicators through a driving process -- and I have time and rural roads. So the Smog Referee was the best path to get it done.

Good Luck!

[alexmurp]

i am a shop foreman at a porsche shop in ma. and have a 96 993 there there now and have tried everything to get this car to pass and in the process of following the cheat sheet to set reddiness. it is a procedure that under normal driving habits reddiness would never set will respond after test if it works. alex murphy

[Jascha]

Alex,

The OBD-II on my '96 will not set ready-states (after ~300 miles and futile attempt at adhering to the recommended drive cycle -which can get you killed!).

The local (non-Porsche) chap does not know what to do (no real incentive) the PA State was not interested in 'the story' and claimed to have no recorded problems in their database...

How did you resolve the stalemate?

[alexmurp]

Jascha there is a lot of cars 96-98 993s having this problem i opened a ptech hotline channel with porsche cars [porsche dealer technicle support] and explained the problem and they didnt have too much to say.but the more i investigate this problem on my own time the more i see this being a real big problem i am going to contact my departmant of motor vehicle and report this problem i will post again hopfully with results and solution alex.

[Jascha]

I did some more digging and came to appreciate that select cars will have inspection exemptions if there is a known problem in monitor readiness completion. Apparently it is possible to obtain an exemption for small volume manufacturer of 1996 cars.

You can check http://techinfo.porsche.com for specific driving conditions required to complete the readiness states. It would seem that the continuous monitors are relatively easy to set. The non-continuous will take specific speeds and other conditions (intake and ambient temperature, altitude, mass airflow, engine load). I called the Porsche Technical Information Support to check if there were any recalls and none were found.

I urge you to press this issue through your respective Dealerships (Service Managers). It might help if you add some gravitas to my official complaint by calling the TechInfo: 1.800.767.7243 (option #3) and report your specific complaints and frustrations…

Keep hope alive.

[Jason Porter]

I can tell you exactly how to fix the SAI problem, as I've done the procedure myself with great success, and it will probably costs you less than $1000.00

In fact, if an LA Pelican wants to get their SAI fixed, I'd be willing to whip up a Pelican-style Technical Article for the procedure.

Of course, this solution doesn't address the cause, so it may very well come back one day. But I haven't had one not pass and keep off the CEL. BTW - I learned this while working at Otto's Venice, and while I was working there we also had a write-up in Excellence about it.

[Don Plumley]

Jason - thanks for your offer, I'm sure at some point someone in lala land will need it. Herg's has a fix as well, I assume it is a similar process. This has been pretty well documented on Rennlist.

But it would be nice to have a definative write up....

[Jascha]

Jason,

Just so we don't confuse and unsettle the 993 community the problems (if you can call it that) with the OBDII readiness monitors are fundamentally unrelated to the SAI issue (!)

The status of all readiness monitors is reset to "not ready" each time the vehicle’s Powertrain Control Module (PCM, the -onboard computer) memory is cleared / reset (example: disconnecting the battery, erasing MIL for whatever reason, including SAI).

To satisfy the readiness enabling criteria --all-- OBDII equipped vehicles must be operated (engaged) through the Drive-Cycle protocol. The Porsche way of doing it is complex and tedious but it is doable…

Thx.

[alexmurp]

Jascha i compiled a list of road speeds and engine speeds needed to set the DRIVE CYLES and to set the reddiness codes there are six of these cycles that all need to be set at one time.what i mean is that if you have five of these cycles set and turn off the key all your work is reset to ZERO. so after many different formulas i ran the car yesterday on my dyno and completed all six cycles you can get five fairly easy its the sixth one thats a bugger SUCCESS!! reddiness set. sticker in hand.

[Jascha]

Pray tell (PM) …I am ready to receive SUCCESS wisdom

It so happens that in PA all '96 are given an allowance of two states not setting.

Five will do just fine!

[tshih]

What if you had a Porsche systems tool or Bosch Hammer reset the fault codes instead of disconnecting the battery? Does anyone know if the readiness should be affected that way?

[alexmurp]

hi if you reset the fault codes or dissconnect the batt you lose the reddiness codes and under any condition the cycle flags WILL NOT set just driving the car for any amount of distance ive tried to set the cycle flags without the porsche system tester and there no way to verify that all the cycle flags have been set so there no way to set all 6 cycle flags one by one without seeing the process being moniterd and verifying that one by one they are going through i put the car on my dyno and run the car in a controlled condition [no traffic] and set all 6 flags in a couple of hours max dont know how were going to do a C4 cross that bridge when we get there alex..

[Paul Crowther]

I live in an area of Virginia without smog testing (yet). Do I have to be concerned about the readiness state of the sensors, as we're discussing here?

Paul

[Don Plumley]

If you don't have smog testing, you should not have worries about SAI or readiness codes at all. You'll just want to make sure any CELs are not non-smog problems. For example, a CEL for a pre-cat O2 sensor needs to be fixed, but the post-cat (sensor 2) sensor is no big deal.

Lucky!

[Jeremy Cottrell]

Originally posted by Jason Porter
I can tell you exactly how to fix the SAI problem, as I've done the procedure myself with great success, and it will probably costs you less than $1000.00

In fact, if an LA Pelican wants to get their SAI fixed, I'd be willing to whip up a Pelican-style Technical Article for the procedure.

Of course, this solution doesn't address the cause, so it may very well come back one day. But I haven't had one not pass and keep off the CEL. BTW - I learned this while working at Otto's Venice, and while I was working there we also had a write-up in Excellence about it.

I would be very interested in this procedure. Thank You.

[Lorenfb]

Read here for more info on Readiness Codes:

www.systemsc.com/codes.htm