Secondary Air Injection Veterans needed

[Boxstard]

Originally Posted by Vidyashankara

Hey guys, Sorry to bring up this old post.

I have the same problem with the SAI system. Both P1410 and 1411 codes are on. The OEM check valve and change over valves are expensive.

Particlewave, I know you confirmed the Mercedes MTC3095 was a perfect fit for the check value in 986. Can you confirm if the mercedes part for the change over value is also a good fit? The part looks different. How did you make it fit? Do you have pictures you can share?
NEW MERCEDES AIR VALVE 380SLC 380SEL 380SL 380SEC 420SEL 190E OE # 000-140-77-60 | eBay


Also, any update on your little hack on fooling the DME during cold starts? do you have it up and running?

I fixed my SAI last winter, not knowning cheaper MB parts... That changeover valve should work, only the difference is the 90-deg orientation of small nipple but you will be fine with enough length silicone hose.

Did you check if the vacuum reservoir is holding vacuum and the solenoid switch is functioning to apply vacuum to the changeover valve?

This winter I noticed that my SAI motor was running erratically and got CEL... but it was just a fuse on its last leg... New fuse was all it took.

Good luck!

[Vidyashankara]

Originally Posted by Boxstard

I fixed my SAI last winter, not knowning cheaper MB parts... That changeover valve should work, only the difference is the 90-deg orientation of small nipple but you will be fine with enough length silicone hose.

Did you check if the vacuum reservoir is holding vacuum and the solenoid switch is functioning to apply vacuum to the changeover valve?

This winter I noticed that my SAI motor was running erratically and got CEL... but it was just a fuse on its last leg... New fuse was all it took.

Good luck!

Hey! I havent diagnosed any of the parts as yet. Just that I get P0410 and P1411. Once the weather gets warmer, I will start pulling things around and seeing what needs to be replaced. The pump starts up and turns off after a couple of mins, so that should be good.

[boxfix]

Originally Posted by Boxstard

I fixed my SAI last winter, not knowning cheaper MB parts... That changeover valve should work, only the difference is the 90-deg orientation of small nipple but you will be fine with enough length silicone hose.

Did you check if the vacuum reservoir is holding vacuum and the solenoid switch is functioning to apply vacuum to the changeover valve?

This winter I noticed that my SAI motor was running erratically and got CEL... but it was just a fuse on its last leg... New fuse was all it took.

Good luck!

I had a bad vacuum reservoir they are only 20.00 or so. easy to test with a hand vacuum pump. They make these in 2 pieces and glue it together. It should be roto molded. You can buy metal ones from Summit Racing.

The solenoid valves are the same in many German cars.

[Boxstard]

Originally Posted by boxfix

I had a bad vacuum reservoir they are only 20.00 or so. easy to test with a hand vacuum pump. They make these in 2 pieces and glue it together. It should be roto molded. You can buy metal ones from Summit Racing.

The solenoid valves are the same in many German cars.

Reservoir was my initial suspect, read it is a typical failure mode, but mine was fine.

After all my changeover valve was shot, inside diaphragm was totally deteriorated, same with the check valve, rubber diaphragm was gooey.

Yes, the solenoid valve is commonly available, made by Pierburg. I bought the same one cheap to rig up actuation of my PSE valves.

[redciv1]

Hello Particle. What was the outcome with the wiring? Did you make the units.
Also how would I go about finding someone to flash ECU with ROW.

[Gelbster]

Here is a link to help you:
Any interest in SAI delete circuit?

[redciv1]

I just wanted to give a shout out to Particlewave as my 99 was able to be registered successfully after installing the emulator and passing emissions with no issue. Thank you sir!!!

[particlewave]

..........

[mikesz]

Hello all, Getting P0410 P1411 CEL's also. Indicates issue with the SAI. Pump is working fine. I replaced the Change-Over Valve for Air Injection because it was cheap and easy but did not fix the issue. So now looking to get to the heart of the system but before I do that want to make sure I know what I am in for. I cannot see any way of replacing the Air Injection Valve without removing the right intake manifold. I found a Youtube video but he did not remove the alternator. Does anyone have experience with this? There are 6 bolts holding the intake on and the ones at each end seem to be the real PITA! I live in RI and need to get the car inspected. I plan on replacing the vacuum lines with silicon ones and I plan on replacing all components in the system. I don't want to have to do this again.

[Gelbster]

You may have already entered SAI hell. I have. There is more to this issue than just replacing parts, doing the drive cycle and fitting an SAI emulator to test your work.
The hellish part is called "Not Ready" or "Inc"= incomplete. This is the fault that causes you to fail smog even if there is no MIL.
If you read here and on Renntech you will find loooong threads where smart guys flounder at solving this issue.
I am not so smart and I was a contributor to these threads. Eventually I passed the Test but almost immediately the MIL came back on. But I got my Sticker !
2 years later and I still haven't fixed the MIL so I fit an Emulator. Light goes out but the SAI System shows "Not Ready" = FAIL on Durametric, Foxwell and the Smog Station's DAD test machine. They note that the entire SAI system is complete and seems functional. So they say - just drive it ,eventually it will set "Ready". Not yet -after 800 miles 1
So what is next to fix this SAI system ?
To do the diagnosis comprehensively and check your repair, you need a vacuum pump and a means of monitoring the PRE-CAT O2 sensor readings at start-up for 90 seconds.

1. Don't fit an ROW reflash unless you are promised a refund if the DAD machine detects tampering. AFAIK an ROW reflash is detectable and you'll be having a very expensive meeting with the Referee.Otoh , it may be smart to have a stock reflash done. A PWIS tool may be able to set a 'sticky' monitor.

2.Take off the psngr side inlet manifold per the youtube link I have given in previous Threads and replace every component you can reach.See Porsche Parts manual or Auto Atlanta online for parts diag.

3.Consider cleaning the exhaust ports into the heads Ugh ! Search for details.

Most Important - NOTE -the system changed with the later cars. Ignore all the photos earlier in this Thread until you check the Auto Atlanta parts diagrams for dates and details. Don't buy any part until you know which system you have.
Testing/replacing the Secondary Air Pump is easy. There is a similar,cheaper Mercedes SAI Air pump with a nearly identical Bosch part number. No clue if it fits/works.Others may chime in to confirm?
Replacing the other parts is tedious because you need to remove the passenger-side intake manifold. Maybe other parts for access. It is easy to break brittle plastic hoses inadvertently.That means you may succeed in the repair but have to go back again hunting for hairline cracks in the corrugated AOS hose.

4.Keep screen shots or notes of everything from Durametric tests particularly O2 sensor voltage changes during the first 2 minutes after start up.

5, Find on Renntech all the preconditions to set the SAI System as "Ready". Do the Drive Cycle and keep logging the data.

6. Make sure all related systems are functional - O2 sensors, AOS ,ignition system. Otherwise you'll get hopelessly deceived.

7. Replace all the hoses with best quality USA made silicone.Replace all the hose connectors with brass fittings.

8.Note that the '01 and '02 MY is notorious for this 'Not Ready' problem .Same issue for E39 BMW -search "E39 Smog not ready" for more.

Before you refit the Intake Manifold ,test the SAI system. -not just the components, the whole system - electrical,vacuum and SAI air flow. The limitation is you can't run the engine until you refit everything..
Here's the only way I know of testing at the Shut Off Valve for flow/vacuum with the engine running at cold start. Why is this significant ? -because suppose all the components tested 'good' but there is still a failure to get rid of the Check Engine light .
To allow testing for vacuum at the ShutOff Valve with the engine running at cold start , add some vacuum hose via a Tee - after the Change Over Valve(before you refit the Manifold!!). Fit a Brass Tee on the output side of the 12v Change Over Valve. Run the hoses up between the runners of the Intake Manifold. If you don't need it ,you can just plug it. Now you have a hose end to connect a vacuum pump to or a Vacuum gauge/manometer(or your finger tip) to measure vacuum and test the system.
You should should see strong vacuum(12"+Hg) to the Shut-Off Valve at cold-start only. It should collapse when the SAI pump stops running(60-90 seconds). If there is no/insufficient vacuum, the Shut Off Valve will not open to allow SAI air from the pump to enter the exhaust stream.
To fix a problem, you can bypass a vacuum/electrical defect by fitting an extra Change Over Valve+ made up harness ON TOP of the Intake (where it should have been from the factory !!)
If/when you no longer need it just connect the 2 extension hoses together with a 3 or 4mm straight barbed coupler.
If you are clever you may even fit the extra Change Over Valve on top of the Manifold with new, bypass wiring via a manual switch .That way you can manually turn on the SAI vacuum and Secondary Air flow for 60 seconds at start up for 3-4 times to prepare for the Smog Test.
Check your repair by monitoring the sine/flat wave for the O2 sensor voltage at cold startup.
If you remove the Inlet manifold -you may need to remove the Serpentine belt(but not alternator) to access the 6th bolt.
When replacing the 6 bolts remember to use Green Loctite .Use "Earthquake Hold" or a very good magnetic 10mm socket insert or neodymium extension to get the bolts started. It is very easy to drop one !
If you still get "Not Ready"or "Inc"-omplete for SAI and the engine is unmodified, take your Smog Failure Certificate to the Referee(in California) and get a waiver. They will pass it and give you a certificate IF you haven't done any hacks. Hopefully a test vacuum hose wouldn't be considered illegal. Be warned, they will scrutinize everything !
For the 'rest of the story' ,read here:https://www.renntech.org/topic/55085-not-ready-sai-secondary-air-incomplete-smog-test-fail/
If the problem is just no CEL but "Not Ready" try starting the car from cold and running for 90 seconds at 2000rpm+/- 300rpm. If you run at 2800+/- 300 rpm you may get a CEL.This worked for me and got me to pass Smog.
If your O2 sensors are marginal consider replacing all 4 with the same brand. I used Bosch.It seemed to help. The other suspects are old primary cats. We'll assume all the vacuum components are perfect and new by this stage.


Hope this helps you and others who follow.

[mikesz]

Thanks Gelbster. Right now my plan is #2. What about the fuel injectors and AOS? Should I replace those once I get the intake out?

[Gelbster]

My most often quoted phrase is "While you are in there".
My preference is replace/test everything ' while you are in there' because I am very short of time and sadly lacking in diagnostic skills.
Of the few parts i did not replace with new when I rebuilt the engine - those are the ones I am now suspicious of. Grrrr!
Worse, it is highly likely I'll do all the disassembly work to the inlet manifold & maybe alternator and find the SAI parts to be perfectly functional !
Throwing parts at a problem instead of diagnosis is ***. But in this case the parts are cheap and why refit parts that although functional may be close to the end of their life?
Pity about the R&R time though.
Please find links to the generic parts that have been used by others. No need to pay the P-tax if you don't want to.
Hope this helps-must get back to work.

[ddruker]

I just finished refreshing the SAI system on my 2001 Boxster S Tiptronic. I was seeing about once a month OBD code P0410 accompanied by the Check Engine Light, associated with the car sitting for a while, so I assumed I had a slow leak somewhere that was triggering the code after the car sat for a week or more and the vacuum slowly escaped. The code does not occur when I am driving the box more frequently. Like the prior poster, I took the "replace everything" approach since the parts are only about $200 and this project requires a lot of painful/annoying labor.

I replaced all of the plastic lines and rubber fittings with 4mm inside diameter / 9mm outside diameter silicone vacuum hose, 3/16" or 5mm outside diameter brass barbed fittings (one 4-way, one 3-way Y shaped, and a couple of barbed connectors) and about 20 8mm hose clamps, all purchased from Amazon for about $30.00. I used about 5 feet of the silicone hose, I would buy a 10-foot section so you have extra for mistakes.

I also replaced the vacuum accumulator tank $21.00 (993-110-140-03), two of the vacuum switches $17.00 each (7PP-906-270), the one-way check valve $15.00 (964-110-950-02) and the air injection valve $99.00 (997-113-249-90). I would have replaced all three vacuum switches but I only ordered two of them as I am dumb sometimes.

Probably because I have the S with automatic transmission, the following things were different than I've seen discussed in most of the rest of the SAI Threads.

- I had 3 vacuum switches. One controlling the air injection valve, one heading down to the automatic transmission, and one controlling the air intake resonator flap.

- I had a four-way junction attached to the vacuum accumulator, and also a three-way junction attached to the check valve.

- The check valve was plugged directly into the right-hand rubber boot on the air intake resonator.

I accessed everything from above and from the passenger compartment, after removing the alternator. It was VERY tight working underneath the intake manifold - in particular reaching the bolts on the underside of the air injection valve was challenging. A very small ratchet with 10mm socket plus a 10mm wrench did the trick, and I had to remove my gloves and fiddle by hand to get the bolts in from underneath. I also had to remove the intake manifold resonator tube as the lines run underneath it.

The existing air injection valve did not have a gasket installed. I installed a gasket with the new one - the metal gasket is included with the new injection valve.

The system would have been impossible to repair using the existing tubing - after 20 years, the rubber connectors were effectively welded to the hard plastic tubing and to the other various valves and switches, and the hard plastic tubing was super brittle. I broke most of it trying to disconnect the old system, and I was being pretty careful.

The whole project end to end took about six hours, and it was not very fun.

[Gelbster]

Thanks for the description.
With the benefit of hindsight , do you think it would have been better to have removed the inlet manifold ? I ask because that is the method proposed in some of the links/videos.
The need to source all the hoses and barbed brass connectors can take a while so to others who are contemplating this job- be prepared for a hiatus.
Once you've done the job, be ready for another delay while the electronics take their sweet time/miles before the Fault Codes all disappear.
So do this job waaay ahead of your Smog Test.

Originally Posted by ddruker

I just finished refreshing the SAI system on my 2001 Boxster S Tiptronic. I was seeing about once a month OBD code P0410 accompanied by the Check Engine Light, associated with the car sitting for a while, so I assumed I had a slow leak somewhere that was triggering the code after the car sat for a week or more and the vacuum slowly escaped. The code does not occur when I am driving the box more frequently. Like the prior poster, I took the "replace everything" approach since the parts are only about $200 and this project requires a lot of painful/annoying labor.

I replaced all of the plastic lines and rubber fittings with 4mm inside diameter / 9mm outside diameter silicone vacuum hose, 3/16" or 5mm outside diameter brass barbed fittings (one 4-way, one 3-way Y shaped, and a couple of barbed connectors) and about 20 8mm hose clamps, all purchased from Amazon for about $30.00. I used about 5 feet of the silicone hose, I would buy a 10-foot section so you have extra for mistakes.

I also replaced the vacuum accumulator tank $21.00 (993-110-140-03), two of the vacuum switches $17.00 each (7PP-906-270), the one-way check valve $15.00 (964-110-950-02) and the air injection valve $99.00 (997-113-249-90). I would have replaced all three vacuum switches but I only ordered two of them as I am dumb sometimes.

Probably because I have the S with automatic transmission, the following things were different than I've seen discussed in most of the rest of the SAI Threads.

- I had 3 vacuum switches. One controlling the air injection valve, one heading down to the automatic transmission, and one controlling the air intake resonator flap.

- I had a four-way junction attached to the vacuum accumulator, and also a three-way junction attached to the check valve.

- The check valve was plugged directly into the right-hand rubber boot on the air intake resonator.

I accessed everything from above and from the passenger compartment, after removing the alternator. It was VERY tight working underneath the intake manifold - in particular reaching the bolts on the underside of the air injection valve was challenging. A very small ratchet with 10mm socket plus a 10mm wrench did the trick, and I had to remove my gloves and fiddle by hand to get the bolts in from underneath. I also had to remove the intake manifold resonator tube as the lines run underneath it.

The existing air injection valve did not have a gasket installed. I installed a gasket with the new one - the metal gasket is included with the new injection valve.

The system would have been impossible to repair using the existing tubing - after 20 years, the rubber connectors were effectively welded to the hard plastic tubing and to the other various valves and switches, and the hard plastic tubing was super brittle. I broke most of it trying to disconnect the old system, and I was being pretty careful.

The whole project end to end took about six hours, and it was not very fun.

[ddruker]

Originally Posted by Gelbster

Thanks for the description.
With the benefit of hindsight , do you think it would have been better to have removed the inlet manifold ? I ask because that is the method proposed in some of the links/videos.


The need to source all the hoses and barbed brass connectors can take a while so to others who are contemplating this job- be prepared for a hiatus.
Once you've done the job, be ready for another delay while the electronics take their sweet time/miles before the Fault Codes all disappear.
So do this job waaay ahead of your Smog Test.

The parts from Amazon all showed up within a couple of days. The exact parts I purchased from Amazon were:

• uxcell 6mm or 1/4 inches ID Brass Barb Splicer Fitting 4 Ways Brass Cross Barb Fitting Air Gas Water Fuel,2pcs
• Legines Brass Hose Barb Y-shaped Tee, 3/16" T Union, Barbed Tube Pipe Fitting, Coupler Connector Adapter 2 pcs
• LTWFITTING Brass Barb Splicer Mender 3/16" Hose ID Fitting Air Water Fuel Boat( Pack of 10 )
• uxcell Steel Band Clamp 8mm for Fuel Line Silicone Hose Tube Spring Clips Clamp Silver Manganese Steel 20Pcs
• High Performance Silicone Vacuum Tubing Hose, ID 0.16" (4mm), OD 0.35" (9mm), 10 Feet per roll (3 Meter), Black 60 psi Maximum Pressure

It's very hard for me to answer your hindsight question. I went the alternator route because I had already replaced the air oil separator on my box, which required me to remove all of the hoses connected to the AOS plus the throttle body and the cross-tube - so I felt comfortable taking those components off again. Removing the alternator was easy - and I didn't come close to breaking anything during that part of the job.



I was worried about removing the intake manifold and potentially breaking more stuff only because I have never had the manifold off before - but doing so would definitely make this project easier, by giving much better access to the vacuum reservoir, the switch and the air injection valve and all the plumbing that sit underneath it.



I hope this helps. I guess the net is that if you are comfortable removing the intake manifold, and you can see how to get access to all of the bolts holding it onto the engine block from above, then that would be easier. If you have to take the alternator out to get the manifold off, then removing the manifold is a redundant step.

[mrmoto444]

@particlewave,

I'm going through the SAI torture process and would love to hear more about your kit to present the "ready" signals. If you could, please send me more information on that kit. I you don't have the kit, I'd be happy to assemble or replicate what I'm guessing is an electronic assembly to present differing signals to the ECU.

Being a total newbie on this forum, I don' think I have privileges to DM you. I hope you catch the reply to this thread. And, thanks for the work you've put into your forum contributions, and kits to date :-)

Hmm... In case you're skeptical about a guy from CA asking for a... "closed-course competition use only, not for highway use" modification, feel free to see some of my other posts from the usual 2-wheel forum I used to hang out on...

https://advrider.com/f/members/mrmoto.6725/

- Scott

Originally Posted by particlewave

I'm going to go ahead and order the components to make 5-10, but I want to run this one on my car for a good 3-4 weeks to give it a good shakedown and address any bugs that might pop up. I'll try to drive everyday so it cycles the SAI as much as possible and monitor emissions components on the Durametric.

If everything looks good, we can go from there. Sound good?

I don't foresee any issues at all and I would think even California guys could get away with it as the system should show ready and the only time emissions would be high is at cold start. If you drive your car to the emissions check, it shouldn't trigger the SAI when they test it, but that depends on how long it sits before they get to it.