Lorenfb

Right, in that case the monitors only appeared (or started to appear) after the completion of two trips and
not in "real time" throughout the driving procedure as stated.

Lorenfb

This is NOT a 993 where setting monitors is very problematic and it's not even a Porsche! Based on the steering wheel logo, it's Chevy.
The point is that different vehicles, i.e. especially the 993, perform the monitors procedure differently. Not only do many 993 owners
have problems setting the SAI, but other monitors are problematic too, e.g. the CAT monitor. So, that post has basically no applicability.

Jay777

Very observant. The post was about the OBD reader.
The rest of the class may now go home.

Mark in Baltimore

Loren, give it a rest, please. Jay is simply posting what has worked for him, and there is a purportedly clear path to help people resolve their emissions quandaries. There is no need for you to do your usual thread-crapping. Alleging that Jay Photoshopped his images is an insult without merit.

Rennlist should not be a place where people are afraid to share new ideas. The general trolling and lack of civility on the board will not be tolerated.

Lorenfb

Any comments on the ECM data posted from the 993 using the Porsche tester, i.e. from the 993 that was used as a test vehicle
for evaluating when completed monitors are displayed using a generic OBDII scanner?

Lorenfb

My apology to all for not having fully tested ’97/’98 993s prior to my assuming
that all three 993s (’96/’97/’98) have identical OBDII monitor functionalities
and that monitors didn't appear immediately once completed on a generic
OBDII scanner.

Today I had access to a ’98 993;

1. First, I scanned it using a generic $20 scanner. It indicated one monitor set (SAI)
and two fault codes (O2 & CAT).
2. Reset the fault codes (CEL) and re-scanned for monitors. The SAI was still set.
3. Used the Porsche PIWIS tester to do a Short Test (forces a monitor to run)
for EVAP. It passed that monitor and it was indicated on the generic scanner
as having passed with the previously set SAI monitor.
4. Again, tried a CEL reset which had no effect on the two previously set monitors,
i.e. the two remained.

Summary;

1. For a ’98 993, monitors appear on a generic OBDII scanner as they are completed.
2. A CEL reset does not reset previously set monitors. Most likely a battery disconnect will.
3. One driving trip under the right conditions may set all monitors without having
to cycle the ignition switch and start a second trip.
4. If a driving trip doesn’t set all the necessary monitors, another trip can be started
on another day without losing the previous set monitors.
5. If a fault code appears before a trip, e.g. SAI, or during a trip, the fault code can be reset
at any point during trip without affecting the previously set monitors. This would easily
allow the completion of less than 5 monitors for states the allow such and avoid a CEL
at the time of the emissions test.

Conclusion:

As has been inferred in this thread, Porsche modified the monitors procedure in the
’98 versus the ’96/'97 allowing it to function as in the 996 and other vehicles, i.e. allowing
monitors to be indicated as they’re completed. Most likely all the features in the ’98
OBDII firmware exist for the ’97 993. All aspects of the ’97 versus the ’98 need further
testing, though.

Hopefully, as more Rennlist members are confronted with setting 993 monitors, more
insight into this issue will benefit all.

Jay777

Just to make sure we stay on point....


Our Goal:
Help as many 993 owners as possible pass emissions with SAI problems

The Approach
Identify a drive cycle that makes 3 readiness flags READY on your car, one of them not being AIR.


Why it works
-In many states, you only need 3 readiness monitors READY to get tested
-If your AIR monitor isn’t READY, your OBD system won’t throw codes or light the CEL - even if your SAI ports are welded shut.

It works in CT
It can work in many other states

I know because I passed emissions this way.
I repeated it 4 times.
I can do it anytime I want.

The drive cycle I posted works on a 97 C2S
You may find a different way – shorter, faster, more fun….whatever. Doesn’t matter how you get there, just get there.

You will pass emissions.
You will smile


Remember:
Don’t make it complicated.
I found my drive cycle simply by driving around until I got 3 GREEN LIGHTS on my AUTEL OBD reader. That simple.

The hardest part was the experimentation it took to make sure it was repeatable. The drive I came up with isn't much fun to do but it worked. The season came to an end before I could do more testing but I did manage ONE TIME to get the monitors where I wanted them while having a lot more fun….

I reset my OBD with my AUTEL, putting the OBD in the state that has been the starting point for all my tests: no CEL, no codes, 5 UNREADY monitors, then began a spirited 27 mile drive up my favorite back road making no attempt to constrain speed or RPMs. (993, twisty, no traffic, beautiful day - use your imagination). At mile 27 I turned the car off, restarted, and doubled back. At mile 44 HTR went ready. Sometime before mile 51 CAT went ready. Back home at mile 54 I idled for a while in the driveway and EVAP came on. Three READY, done. Don’t know why or how this worked, but it did and it was a lot more fun than getting run over on the interstate doing 55.

The point is that there’s more than one way to skin a cat. My run works on a 97. You may need something different. That’s where crowd testing will come in. If you find something that works, tell us about it. You will need an OBD reader to do this. Way cheaper than a SAI port Roto-Rooter. I Iike the AUTEL because it has everything you need on one screen in color, which makes it easy to see while driving. The Cen-Tech unit I have works but it’s hard to read and you have to scroll the single-line display to see each monitor. Pick one you like. I have no connection to either company.

One more thing…
This concept only works in states that don’t require all 5 monitors READY (more specifically: don’t require AIR to be READY). EPA guidelines require only 3 to be READY and states generally follow EPA guideline but don’t have to.
Of the 31 states that require emissions testing 21 currently indicate they only need 3 READY, so at the very minimum, two-thirds of the states allow this. CA needs all 5. We don’t know what the rules are in the remaining 9.

Source: http://eti-home.org/State%20I-M%2020...roduction.html

So what we need to determine is:

1) How many readiness monitors are required in the following states:
DE, DC,IN,ME,NH, PA, TX, UT?

2) In all states: Is AIR one of the monitors allowed to be NOT READY? I don’t think this will be a issue as preliminary checks seem to indicate states are most concerned about CAT, O2, HTR. Possibly this is because the secondary air system only runs briefly after a cold start.

So, soliciting help from others. All it takes is a call to a local emissions station to ask: “Which readiness flags have to be READY before I can get tested”? That’s all I did.
If you report back what you find I'll summarize and post the results.
-Jay

Lorenfb

Tested a 986 (Boxster), same as 996, for a reset of a CEL and its effect on existing monitors to determine
whether all monitors are lost, which is the case for most all OBDII vehicles. The CEL reset deleted all the
monitors.
Summary of 993 monitor setting characteristics:

'96 993 - DME ECM PN - 993 618 604 00
1. Typically requires 3 trips without any fault codes
2. An incomplete trip must be repeated, e.g. all monitor cycle flags not complete & ignition switch cycled
3. No monitors will be indicated on a generic OBDII scanner until all trips are successfully completed.
4. A CEL reset deletes all previous set monitors.

’97 993 - DME ECM PN - 993 618 604 10
1. Requires two trips without any fault codes
2. Monitors begin to appear using a generic OBDII scanner on the second trip (updated per post #74).
3. A CEL reset deletes all previously set monitors.

’98 993 - DME ECM PN - 993 618 604 11
1. May require just one trip
2. Monitors begin to appear as each monitor is completed when using an OBDII scanner

Jay777

There's an interesting EPA document entitled "Performing Onboard Diagnostic System Checks as Part of a Vehicle Inspection and
Maintenance Program" that has a lot of useful information about the OBD testing procedure.

Page 7 and 8 list EPA guidelines for failure or rejection of the OBDII emissions test. The guidelines are also shown as a flow chart
in Appendix E.

Surprisingly, the PASS criteria is quite simple:

1) The CEL bulb has to be functional
2) The CEL has to be OFF
3) The minimum readiness monitors need to be set READY

Note that there is no mention whatsoever of "Drive cycles", "cycle flags" , trips being "complete" or "incomplete", etc.
Emissions doesn't care about this stuff and neither should you. If your CEL is functional and OFF and you have the minimum
readiness monitors READY, you PASS OBD. Your OBD reader will tell you this before you go to emissions.

As far as minimum number of readiness flags, Note 6 at the end of the document states:

"EPA has revised the current readiness code requirement to allow states to complete the testing process on model year 1996 thru
2000 vehicles with two or fewer unset readiness code; for model year 2001 and newer vehicles, the testing process could still
complete provided there is no more than one unset readiness code. It is important to understand that the vehicle does not fail the
I/M test because an unset readiness code is not itself an indication of an emission problem with the vehicle"

Why did they do this? Because vehicles were having difficulty setting monitors and for some vehicles it was even impossible to set certain monitors. (see Appendix D)

These are EPA guidelines. Most states follow EPA guidelines, some do not. CA is one.
You should check with your emissions to verify what you need to pass.

For those interested in reading more, the attached pdf is the full EPA document.

Jay777

The attachment

nine9six

SUBSCRIBED
Very informative thread. Rennlist at its best, IMHO!

Jay777

Thanks nine9. Hope you can benefit from this workaround someday.
BTW, I incorrectly stated in post 32 that the technique wouldn't work in CA. The 49 other states currently follow EPA guidelines of allowing TWO not ready monitors, CA tightened things up a bit in May, 2015 and now allows only ONE not ready for 1996 to 1999 vehicles (Slides 2 and 3 in the attached). (Others stated this but I drew the wrong conclusion from their post).

So an SAI Drive Cycle for CA will be one that gets all monitors ready except AIR. That may not be as hard as it sounds since AIR requires a cooldown - something that's easy to avoid. Coincidentally, when I did the emissions test referred to in post 1, AIR was the only monitor not set (post 34), so it's possible. Don't know how I got there, but we'll figure that out.

Stay tuned...

Jay777

It was a nice day so I decided to try and repeat the "3-Monitor Drive" that I reported on in post 67.
More details this time:

- 2:30 pm: Cold start, idle in driveway long enough to connect the Autel AL519 scan tool.
RESET the car's OBD system. 5 unready monitors, no codes, no pending codes, no CEL.
Reset tripmeter and drove off.

-Spirited 26 mile run to next town on twisties, making no attempt to constrain RPMs or speed. 2 miles of stop and go in town to 26 mile mark where I truned the car off, removed key and sat for 30 seconds.

-Restarted car. 5 unready monitors, no codes, no pending codes,no CEL

-Headed back on same route, driving in the same manner.

- At mile 42 the HTR monitor went READY. (I was actually looking down when it changed from RED to
GREEN). One down, 2 to go.

- At mile 52 CAT monitor went ready. 2 down.

- 4:05pm: Back home at mile 54. Without turning car off, idled 30 seconds until EVAP went ready.
54 miles, 1:35 minutes, 3 monitors. I can pass emissions in 49 states even with my bad SAI.

It doesn't get much easier than that, guys -a fun drive to boot.
I was amazed to see how closely the points at which the monitors tripped matched my previous run, given that "spirited drive" can mean different things on different days. Comparing the 2 runs: HTR went ready at mile 44 and 42. CAT went ready at mile 54 and mile 52. EVAP after less than a minute of idleing.

Very encouraging. Hoping others will give it a try and report back.

-Jay

Lorenfb

Today I visited another of my SoCal independent Porsche shops that provided access
to a ’97 (6/96) 993. The following OBDII monitors test evaluation was performed:

1. Initially all 5 monitors were set. The AL519 scanner was used to do a CEL reset.
All 5 monitors were deleted as a result.
2. First, both the SAI and the EVAP were done (short tests) using the Porsche PST2 tester
to begin the 1st trip. Neither was displayed using the AL519.
3. The 1st trip was completed per the tester indicating all 5 monitor cycle flags were present.
The AL519 was used to evaluate the completion of the 1st trip, but no monitors were indicated.
4. The 2nd trip was begun by again setting the SAI and EVAP cycle flags. Neither of these
were indicated by the use of the AL519.
5. As the cycle flags completed during the 2nd trip per the Porsche PST2, the AL519 never
indicated the completion of any monitor. Even with just one monitor (CAT) left to complete,
the AL519 still indicated no monitors completed.
6. Once all the five monitors of the 2nd trip were indicated as having completed via the
cycle flags using the PST2, the AL519 indicated all 5 monitors as completed.

Based on these data, the ’97 993 evaluated today functioned the same as a ’96 993 with
the exception that only two completed trips were required for all monitors to be indicated by
a generic OBDII scanner (AL519), i.e. none were indicated before completion of all the
monitors.

Here's info on the 993's firmware per the PST2 Porsche tester:



As can be noted, the DME ECM is a - 10 ('97 993 per Porsche PET)

Ivan J

I've been following this thread out of curiosity. Having a '95, I don't have to worry about SAI problems. Unless I missed it, we're missing a key piece of information... the firmware revision information from Jay's DME. Perhaps there is a range of firmware revisions that behave as Jay has described, and others behave as Loren has described? Jay, can your scanner read the firmware revision info?