mac993

I know this subject has been brought up before but I haven't heard or seen anything on it recently.

Has anyone figured out how to clear the codes once the drive cycle has failed? I have no CEL light triggered nor do i have any SAI issues. My readiness code just will not clear. I have my car taken care of my an A+ shop here in SD and the car is perfect outside of these readiness code (in fact they say its one of the best condition 95k mile cars they've seen). Smog is due soon and Cali is no longer allowing the Smog ref to pass a car more then one time with this issue. Need some help from my Rennlist brotheren......

User 122821

Just drive this twice

Start engine, let idle for approx. 2 min, 10 secs.

Accelerate to 20-30 MPH, Maintain steady speed for approx 3 min, 15 secs.

Accelerate to 40-60 MPH, Maintain steady speed for approx 15 mins.

Decelerate and come to a stop. Then:

Idle in Neutral for 5 mins. (manual trans.)

Idle in Drive for 5 mins. (Tiptronic trans.)

During the drive cycle, do not exceed 3,000 rpm or 60 mph.

NN3

I am in the same boat. Yeah, went to state ref. and no luck. I will keep try the drive cycle this week. Good luck.

gonzilla

You didn't do the drive cycle right. You need to do it twice. Buy an OBDII reader and take it along with you when you do it so you know when you've completed it.

User 122821

I was able to drive it twice on one night and set all but one of the readiness codes. The main hurdle is finding a road that this process is possible to drive.

CorrdoBrit

This one is cheap and cheerful and gets the job done. A nice feature also lets you know if your car will pass emissions using colored LEDs.

http://www.amazon.com/Equus-3030-Inn...3175615&sr=8-5

mac993

Thanks for the feed back but the drive cycle has been done a number of times on a dyno and still no luck.... It's getting pretty frustrating!

MarkD

wow, sorry... I'll bet it is frustrating.

We've never had it not work though I have never tried it on a dyno.
You do not have to drive all steps in sequence and as long as the maximums are not exceeded you can continue.

Some of the codes must have set... which are not "clearing"?

Lorenfb

"You do not have to drive all steps in sequence and as long as the maximums are not exceeded you can continue."

Correct, but certain steps MUST complete, i.e. SAI & Tank Venting, or ANY
amount driving is a waste of time which is the case for many. Also, the state of
the emission systems can effect the total time, e.g. some readiness setups
have been done in less than 45 minutes.

diet97993

I've gone through the same issue with only (3) of the monitors setting right off the bat. I'm also between a rock and a hardspot since I've already been to the Cal referee twice already in the last 4 years. I've driven the above mentioned drive cycle 4 times with once being on a skid pad with no suscess utilizing the OBD II monitor. I've got a month before I'm due smog again and hoping there's a remedy. Oh, and by the way I haven't had any CEL issues. This originally began when my battery went dead several years back. This is really becoming a royal PITA!...... Is there the possibility of a bad ECM causing this?.....Just a question.

cosmic_993

Would it be possible to do the drive cycle on a lift with the wheels in the air?

mac993

MarkD- Not sure of the codes as I do not have a OBD II scanner. I just swing by the shop every now and again to see if they are still there.

diet97993- That is the exact situation I have. Been to the ref 2 times in the past 4 yrs and my reg is due in July. I have 3 codes that won't clear and haven't for 5+ yrs..... It's crazy. What is worse is that my car runs PERFECT and passes out the pipe with flying colors yet in 2 months time my only solution as of right now is a whole new ECU or the state of Cali will pull my car off the road.

cosmic_993- Not sure have often wondered the same thing myself....

diet97993

Mac993 your situation is identical to mine to a tee. I too passed the emissions (tailpipe) HC and NOX with no problems both times. I know there is a repair cost limitation $$ placed on the replacement of smog related components and once thats been exhausted you were able to apply for the referee for a determination. The only other thing to do is contact the California Air Resource Board (CARB) direct and ask for the determination as to why the rule changed from their previous action pertaining to this subject. I personally know there is history on record with them when it comes to the 993. I'll go back through my correspondence with them to see if I can find the CARB representative's phone number. As far as an area to perform the drive cycle you may ask one of the high schools possibly the auto shop instructor if you can use one of the parking lots as a skid pad on a weekend when no one is there. You should be able to manage a wide enough initial arc from center for the 20 - 30 MPH portion of the test to sustain a constant speed for 3 minutes, 15 seconds and then again increase the radius of the arc for the 45 MPH for 15 minutes portion. This would also keep you from being a traffic chicane on the local streets with folks wondering what the hell your up to. Years ago (1970's) when I worked on F-5000 (Surtees TS-11) cars we actually used a HS parking lot as a skid pad in the San Diego County area with "permission" of course since the nearest track at the time was Riverside Raceway.

Lorenfb

"I've driven the above mentioned drive cycle 4 times with once being on a skid pad with no suscess utilizing the OBD II monitor."

Then most likely there's a problem with the emissions system, e.g. Tank Venting,
or the O2 sensors. Additionally, air mass meters have prevented readiness codes
from setting but have not generated a CEL. Remember, to set the readiness codes
it requires a minimum of two trips and if the 1st trip doesn't complete (all monitors
being successful) the second trip is a 'waste'. For problematic 993s,
use of the Porsche tester is required. Also, stall the engine during a trip
and the trip MUST be restarted, i.e. one loses all successful monitors
of that trip.

Bottom line: It's not as easy as some would suggest.

Check out this for more info:

http://www.systemsc.com/codes.htm

MarkD

exactly why I asked what was NOT setting.

Depending on which is holding things up it could be a simple repair...
otherwise, as Loren stated, Porsche tester to diagnose.
Paying someone with the tester will likely be cheaper than shotgunning parts