Harvey Yancey

Just got this from pca.org. Written up by two Porsche mechanics. Really interesting:

Peter Smith: "The readiness codes on a 993 are impossible to set if you drive the car like you are supposed to. There are 6 cycle flags that need to be set to create 1 trip and you need 2 trips to set the readiness codes that say that the air injection, evap, and the oxygen sensor are working correctly. But to set these codes is the hard part. One of the factors is that you have to drive the car at about 2100 rpm for a total of 5 minutes to set one of the cycle flags. I can get 2 trips in about 45 minutes. You need the PST2 to do a short test for the air injection and evap system s and then after running the car for 4 minutes and 10 seconds, hold the rpm at 4000 for 90 seconds to set the part load adaptation flag and then let idle for 90 seconds for the idle adoption. Then drive the car for 5 to 7 minutes at a continuous 2000 rpm to set the aging flag for the oxygen sensors. The PST2 will tell you that the flags are set and then you need to go to status checks to see if a trip has been registered, if it has, you shut off the car and start all over again for the second trip and then the readiness codes should be set. All 6 cycle flags have to be set during a driving cycle, if you set 5 and shut off the car, you start from scratch the next time you start up the car. It was a pain in the but to figure this out but we were forced to, to smog cars".

Scott Slauson: "To achieve the Ready Status the car will require 2 trips. This is the easiest achieved with either a Hammer or another Porsche tester. The air pump and tank vent checks can be acti vated under the Short Tests. All other tests can be achieved by either running the car parked or driving it. Shou ld it be done parked you would still have to drive it for a very short distance (1/8) mile to register the trip. Now once it shows a Trip you must cycle the key and start all over a gain. This second Trip will give you the Ready Status. I often do these for the customers and charge 1 hour. I have seen many cars driven for a couple of thousand miles and not show any trips. Should the key ever get turned off before the Trip has occurred you would start all over again."

MarkD

Great info Harvey
That explains why it took 2 trips when I did the routine in my 993tt! No hammer or PST2... got lucky on the first trip and triggered what needed to be triggered.
Also explains why people say the drive routine doesn't work.
Thanks!

I know many say referee station is the way to go... but with this info, I could hit it the first time and be done with it.

1pcarnut

This would be good news if you can do it parked! After seeing the near impossible to achieve sequence that has been suggested on other threads, this would be great. Does this mean we combine what Peter and David are saying? Such as when Peter says to drive the car for 5 minutes at 2100 rpm does this mean we can just hold the throttle open at 2100 while parked and not under load?

Also, Peter's comment about "hold the rpm at 4000 for 90 seconds to set the part load adaptation flag" seems to contradict what other threads have said about never going over 3000 rpm when trying to set the flags.

If this really works can we get a step-by-step sequence from these guys for us dummies without testers?

Robert Collins - 96 993TT

Thanks Harvey. I just drove from Nashville to Charlotte and back for the parade, and my damn codes never set. I thought 100 miles would surely get it along with several low spirited drives around town. No dice. I will try this next and report back what happens.

g_murray

Long story short: the PO let the battery die before I got my hands on the car.
I drove 700 miles before the readiness monitors would ALL set (there are 8). *THEN* and only then I could bring it to the NY inspection station (for the OBD-ii tests) and get my sticker.
Now I *never* let the battery 'go' - and, of course, have a trickle charger for the winter-time.


Gerry

jimhsu

This is very interesting info....

In my opinion, emissions testing by OBD instead of testing the actual exhaust is the biggest nonsensical decision.

Nothing matters to the environment except what comes out of the tailpipes....so why not test that instead of scanning the silicone chips? We all know how RELIABLE those sensors are....

This info only goes to show that not all OBD readiness protocols are created equal (Porsche's is much stricter than others) and it creates more headaches than necessary.

Every time I drive by an emissions testing station and right next to it there is a prominently advertised "EMISSIONS WORK DONE HERE" auto shop, I smell the ingredients of a scam.

ecobb993

Interesting . . .

I've had great success using the BMW routine which just takes a minor side trip on the way to the inspection station:
http://www.srlx.com/p-car/obdii_readiness.pdf

jackb911

The above described BMW routine works fine for me as well.

Robert Collins - 96 993TT

Thanks for that info. I saw that elsewhere, but that pretty much confirms that I should try it. I will take that graph out this weekend and try to set them.

I will post back soon, hopefully.

ecobb993

My independent shop gave it to me several years ago (they service all German makes). Seems to work just as well for 993s as it must for BMW, so I uploaded it to my server and linked it here. It was so popular, I also put a link on the DIY page.

Glad to see others are having similar success with it. Maybe it'll take a little of the SAI pain and stress out of owning a 993.

jimhsu

count me as one of the many however who tried your routine many times and could not get the readiness to be set....again how reliable are those sensors?

ecobb993

jimhsu:

Very interesting; wonder if it depends on which code is being set. I've only needed to set the readiness code after clearing the SAI error.

Rhino

Maybe I am not seeing something here but when I look at the BMW graph example, it says at the end to idle in gear for 5 min. Does this mean keep the car in gear with the clutch compressed? Or what? Thanks for the clarification. I plan on trying this over the weekend

If this does not work, do any of you know someone in the bay area that can set the codes?

ecobb993

Seems like that's the only answer. I think they're trying to emulate sitting at a red light (although 5 min sure is a long light). Mine's a tip so I can't confirm for sure.

MarkD

M/T cars do not need to be in gear for the idle part.

Just to add my .02, following the "BMW" drive routine did work for me, however, it was very hit/miss. Took multiple attempts... and probably involved some luck. Some of the readiness codes were easy to set but I cannot recall which. Setting them all was a challenge.

If I needed to do this again, I'd try the routine Harvy Yancey posted above to see what happens.