mac993

Loren or Mark- Wow thanks for the info! Could this be done on a lift or with the rear of the car jacked up (safely and properly of course)?

MarkD

I am sure Loren will correct me if I am wrong but I am pretty sure the engine needs to be under a load.

At one point I had a doc that stated load values required but I can't find it at the moment.
Unfortunately, freewheeling on a lift will not work.

This is why I was a bit uncertain of doing this on a dyno... theoretically it could work but I don't know for sure.

Slow Guy

Mark, isn't it bad on the CV joints to drive the car like that with the wheels off the ground? I I thought I read somewhere that it was highly discouraged.

vjd3

I had the same problem, did the cycle a few times, always the same 5 not set, gave up and drove the car for a couple hundred miles, they reset themselves. Good luck!

MarkD

ah, yes... that too. Probably not a good thing to do for an extended period. The CV joints hang at an extreme angle when the suspension is unloaded.

Lorenfb

"I am sure Loren will correct me if I am wrong but I am pretty sure the engine needs to be under a load."

That's correct. The load is a a key factor and is why certain RPMs at certain
speeds are required.

"The CV joints hang at an extreme angle when the suspension is unloaded."

Another key point is the fact that the whole drive-train is lashing back-and-forth,
i.e. hard on all the gears, with it being unloaded with shifts.

diet97993

LorenFB, Thanks for the information concerning the CEL and the possibility of marginal emission components that won't trigger a CEL. I will have to make an appointment with my indy or the dealer the only problem for me is their 50 miles away in either direction. But you do what you have to do based on the situation.

Mac993,

How many of your flags have set? Curious to see if they are the same as mine.

So far the three flags the car has set are flag #1 Catalytic Converter Efficiency; #2 Oxygen Sensor Aging and #3 Secondary Air Injection System leaving Tank Ventelation System and the 1 (TRA) and 2 (FRA) Adaptation Ranges not setting. I also noticed in the #2 Adaptation Range you must maintain an engine load of less than 1.2ms (whats that, and how would you obtain it?) for a constant 60 second period at some point from the 4 minutes 17 second point through 17 minutes and 5 seconds of the drive cycle. the #1 Adaptation Range requires engine speed greater than 920 RPM for a duration of 60 seconds. This is per the OBD II manual for the 993 page B-4. Not really sure, but I beleive in california a "minimum" of 5 flags set is needed in order to pass inspection??

Don

mac993

Don-
Not sure. Don't have a reader. I just stop by my shop every now and again to check. Next time I will find out what hasn't cleared. As far as smog I've heard that a smog check station can pass you with 1 flag triggered and the ref can pass you with 2. Anything above that and you are SOL.
Dan

Loren and Mark- So what I am gathering is that the drive cycle is the ONLY way to reset these codes?

vincer77

A dyno may not load the car in the same way that it would be in normal driving. A spinning roller or a water brake is not the same as a car driving on a road. I think (IMESHO) you really need to run the cycle on the road.

Lorenfb

"So far the three flags the car has set are flag #1 Catalytic Converter Efficiency; #2 Oxygen Sensor Aging and #3 Secondary Air Injection System leaving Tank Ventelation System and the 1 (TRA) and 2 (FRA) Adaptation Ranges not setting."

TRA, FRA and Tank Venting are related in that if there is a leak the TRA & FRA
will attempt to correct for the leak which could put both at their limits.
That's why using the tester will eliminate both Tank Venting & SAI as a
problem source even before driving begins, and thus facilitate setting of
the monitors.

diet97993

Here is the individual's name (Neil Hart) and number (661-833-6304) that I talked to some time back (2 years ago). He's with the California Buearu of Automotive Repair. He was aware of the situation concerning the 993's OBD II problems at the time.

Don

diet97993

Went down to the Santa Barbara Auto Group who is the local Porsche dealer. Attempted to cal smog it and no dice. The three that are set are:

Misfire

Fuel system

Comprehensive Component

Not Set:

Catalyst

Evaporative System

Secondary Air System

Oxygen Sensor

Oxygen Sensor Heater

Smog Tech decided not to formally smog the vehicle. The Porsche Tech placed the car on the PST and read the same thing concerning the flags. However, when he performed the diagnostic and checked all the operating parameters of all the monitors individually there was nothing that was close to being out of tolerence or near marginal. Forgot to mention that I performed "two" seperate drive cycles (4) trips and noted no change or setting of any additional flags (readiness indicators) . The Tech told me that the DME operates just fine and tail pipe emmisions are well below the states requirements and the car runs strong. For some reason the five monitors will not complete. Their recommendation is take it to the referee. They also mentioned that most of the 993's they've seen (96 thru 98) are experiencing the same problems. The tech indicated that the Referee here is well aware of the problems with these cars and has passed them here recently. At first the service manager indicated to me that they could flash the DME and reinstall the software but was later recanted by the tech saying that Porsche no longer supported the 993 software. However, if this should not be the case with mine I was quoted $2,500.00 for a new DME installed from the dealer....stealer. Is there any other source for a DME besides the stealers? Since everything else runs fine and the monitors indicate they are working is there a chance that this could be in a connector or wiring to the OBD II? Could there be a DME grounding issue?

Don

diet97993

Well.....looks like folks lost interest in this subject for the time being. As I learn more about this I will post what I find and hope this helps when someone else is faced with the same problems. There must be some resolution to all of this besides purchasing a new DME.

Mac993, Hope you understand that I'm not trying to hijack your thread just trying to keep the issue open since it does affect many 993 owners.

Cheers!

Don

mac993

Don- No hijack at all. I am VERY interested in what you find out. I think you and I are experencing the same exact thing so any info you find out will be very helpful. Also let me know how the ref works out. I have been to the ref 2 times in the past 4 yrs and he was very aware of the problem. The issue I am hearing now is that regardless of their knowledge of the issue a car can only be issued one exemption (I have now had 2). My smog is due in July so I am very worried.....

diet97993

Mac 993, mine is due in June.....I too have 2 exemptions. I'm going to talk with Steve Weiner at Rennsport tomorrow to see if he can shed some light on the subject. Check your DME under the drivers seat and see what DME you have. If you have part # 0.261.204.376 there is the possibility of having it flashed over unfortunately if you have a .203 you may not be able to. If I have to replace it I have an e-mail into Sunset Porsche in OR and JPLV Porsche/Jaguer in Las Vegas to source a new DME. The price from Santa Barbara Auto-Group our local Porsche dealer just seems unrealistic ($2500.00).

Cheers!

Don