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"Not Ready" SAI , Secondary Air incomplete smog test fail


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For the 2001 cars there is a very difficult,obscure Secondary Air Injection ( or S.A.I.) "Not Ready" problem. This is also called "Inc" or "Incomplete".

JFP has mentioned this in the past and we've had a few sagas here trying to resolve the issue but none as extreme as this one.

The car shows  no MIL/ Check Engine nor any Pending Codes. You won't fail a Smog Test even in California with this problem - your car will be "Declined". Which is nonsense because you won't get a Pass smog test certificate and you'll be unable to get tags for your car. But do pay the invoice !! You will be told by the smog tech to' just drive the car'.
I have been ' just driving'  mine for 2400 miles and 20 months. The SAI according to Durametric and Foxwell NT520Pro is still Not Ready or Incomplete. No codes, no pending codes.
The S.A.I. system works perfectly by any diagnosis-  O2 sensor voltage ahead of Cats at start up(thanks Ahsai). air flow of SAI pump,exhaust posts in head are clean,all SAI hoses and connectors are new/upgraded.Check valve receives strong vacuum while SAI pump operates. All 4 O2 sensors are new but I am open to replacing them all. Which are the fastest responding brands? NTk, Bosch ,Denso ?
Using an emulator(for diagnostic purposes only) in the O2 sensor circuit makes no difference.
The Referee refuses to test the car insisting it goes to the Porsche dealer for repair. That is a blank check because the Dealer speculates it might need a new ECU ,a new SAI system etc. Really the dealer doesn't want to attempt obscure repairs on an old car. The old techs who understood this problem have retired.

The reflash with ROW option is eliminated because the new (DAD) smog machine will detect the abnormal code and your car will fail for 'equipment tampering"
One option is to get a reflash to stock ,hoping that there may have been some bug fixes in the latest reflash . Is this reasonable ? The ECU is a 2001 original and unmolested.
Another option  is to get an Indie with PIWIS to 'force' a Ready status even temporarily and then Smog test immediately. Any recommendations in S.California ?

I have done the Drive Cycle many times. What is unclear is how to prompt the SAI to operate during light load/cruise/2900 rpm - if that is even relevant ? I can do that because I have a plugged  aux vacuum line via a Tee to the Check valve and a bypass switch to manually operate the SAI pump.
This thread may be a good spot to document an effective solution to this problem. It affects very,very few 996 and 986 M96 engines so the usual Internet resources are unhelpful. Any ideas/solutions ?

Thanks for any ideas.

Edited by Schnell Gelb
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Some of the early cars had a real problem getting the IM Readiness test "not ready" status to change without resorting to the PIWIS, even after all the necessary repairs have been completed. I have personally seen cars go more that 200 miles of daily drive cycles before the system switched to "ready", but I have never seen or heard for one going 2,400 miles.  I would have to agree with Loren on this one; something is still not right.

 

If the O2 sensor ahead of the cats goes to a straight line zero, or near zero voltage while the SAI pump is running, the system is functional.

 

Before repair

spacer.png

 

After repair

spacer.png

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JFP and Loren, Thanks for your insights.

Neither of my O2 sensor readings before the cats go immediately to the flat line value shown in the second("After Repair") graph. I get about 0.040Volts or less but it does fluctuate below that value.

You have to be really fast at clicking through the screens on Durametric to get to both pre-cat O2 sensor voltage graphs to see the critical activity during the 90 seconds or less that the SAI Pump runs from cold.

I'm going to try another set of new Bosch O2 sensors to see if that makes a significant /effective difference.

Many thanks for the help. Yes, 2400 (illegal) miles while desperately trying to get legal is an awful benchmark.

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  • 2 weeks later...

Suddenly the SAI system is READY !

As an irrational attempted fix, I bought 4 new Bosch O2 sensors. To develop a base line to compare before /after new O2 sensors I ran Durametric to plot the pre cat voltage for both banks. I plotted the voltages and then out of habit  checked Ready Status and was incredulous that all Monitors showed "Pass" . Obviously a glitch in Durametric? So I tried Foxwell NT520 Pro. It also showed all Monitors Complete. Without turning off the engine I zipped off and got a Smog Test - at last- after 2 years of futile flailing.

So what caused the SAI monitor to get "Ready" after so many miles/starts/short drives/long drives etc. ? I don't know ,dang ! I am embarrassed to say this because I am fairly competent technically and I did a lot of (futile)testing over 2 years. I even tried an 'outlaw' emulator. Yes, I removed it .Ineffective.

The only thing I did differently recently is to let it idle at around 850 rpm for 10 minutes after a cold start. On another occasion I tried 2 minutes at  2500 rpm.

I wish I could tell the few lonely souls who get this problem what the specific fix is . Sorry, I can't but it may be drive cycle related and specifically the idle component.

Good luck with that and please share your experiences here on Renntech so others who follow may avoid driving without tags while desperately trying to complete the drive cycle uninterupted.

There has got to be a better way than what I did !

Thanks to JFP and Loren for their help.

I have 4 new,never fitted oxygen sensors,,,,,,,

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  • 1 year later...

"Not Ready" , "Incomplete" No CEL. The mystery unravels.

Cleared an SAI code caused by not allowing the SAI to complete correctly. Several monitors read "INC" on my scanner. All is good with O2 sensors etc according to Durametric. Persistent "INC" problem for EVAP and Cat.

'Just drive it a while' said the friendly Smog Tech - the one who looked in the rear trunk to do the engine inspection !

Last time it took 1500 miles and 2 years to get all the monitors ready. I think I have discovered why.

Since this problem was first discussed years ago on Renntech many videos and posts have appeared on the www. Many seem to be click bait.

The best ones mention trivial(?) conditions that have to be met in the 7 parts of the Drive Cycle. For example - Start the car on level ground,idle for 2-1/2 minutes,do not exceed 30/60 mph, coast to stop without using the brake (!!) ,no a/c, no cruise control, do not go below 20/40 mph,do not stop,no hills and more. Finding a road where you can safely do the Drive Cycle is difficult and there is no mention of the need(?) to perform the Drive Cycle in one continuous event - no interruptions/no deviations.Certainly ,normal driving would not replicate the Drive Cycle.

So early on a Sunday morning when the road was deserted I followed the Drive Cycle with every extraneous /additional (trivial?)condition satisfied. It worked.

It took about 45 minutes because you have to(??) do it twice, sequentially (?).

It helps to use a timer and odometer.

The scan tool may need to be turned on/off to reset and detect the readiness monitors have set "Complete / O.K." Ideally you need a scan tool that is live so you don't do the dangerous Drive Cycle any longer than necessary. My Foxwell 520Pro was unimpressive.I had even tried driving with Durametric running on my laptop. Not safe !

The best listing (there are many)of the Drive Cycle sequence I found was:

WWW.SMOGTIPS.COM

(RESOLVED - Click To View) My Porsche 911 just failed the smog test because the emission monitors were incomplete... specifically the oxygen sensor monitor. I've driven it for at least 100 miles but I still can't get the monitors complete. Do you happen to know the exact drive...

 

 

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