Not another SAI question...

99three · 08-02-2009, 10:06 PM

Does the CEL indicating the SAI code come on while normally driving, after it's fully warmed up, or while secondary air pump is running?

chris walrod · 08-02-2009, 10:39 PM

Typically takes two drive cycles from cold starts to trigger and store the code.

Deadeye · 08-03-2009, 09:37 AM

Mine comes back randomly300 to 500 miles after I clear it. I don't recall it ever coming on during those precious two minutes at cold start.

99three · 08-03-2009, 07:01 PM

So if I understand this correctly the computer stores two previous SAI codes, then at any time after a cold start up the CEL will light up (in my case it was well warmed up on the freeway going 100, bang...CEL). Is that how it works or could it be attributed to something else since I just replaced the SAI valve?

Deadeye · 08-03-2009, 08:39 PM

Could be SAI. You need to read the code(s) to know for sure.

99three · 08-03-2009, 09:49 PM

I used the Snap On code reader - P0410 code. SAI for sure.

tigerrat · 08-04-2009, 12:21 AM

Hmmm, if you just replaced the valve, I would double check that small, sneaky vacuum hose that attaches to the other check valve that is on the ~ 3/4" hose just above the SAI valve. It is short, hard to see and pops off when you pull the SAI valve. It bit me and I wasn't the first and I bet not the last. Ken

mlucas70 · 08-04-2009, 04:14 AM

But wouldnt that trip both codes ? P0410 and P0411 (left and right bank). I too have just had the Check Valve replaced and experience exactly the same issue as 99three. The CEL goes on at the most peculiar time (on the autobahn at 80mph, in town at traffic lights) etc etc. Indeed it seems to be just the time when probably the readyness codes are about to set and then throws the CEL. I get the all too famous P0410 and clear it with my reader, usually comes on between 30 and 70 miles again.

I always understood that the vacuum hose triggered both codes simultaneously. I have now read a great deal about the SAI, the ins and outs, the do's and dont's, the dreads and fears. What would interest me is where is the sensor that reads and monitors the air injection which decides that air isnt flowing. If it is the O2 sensors, then you would get a different error code.

Changing the Check Valve in my case hasnt really done anything.....

Martin

JStuart · 08-04-2009, 05:56 AM

Same thing here...very random...both banks. I've had it go off 2x in a day...then nothing for months. I was told that it was 10...not 2 cycles. Always happens hot.

Gary Perry · 08-04-2009, 10:13 PM

Going through this right now. My independent shop plumbed bypass lines from the air pump down to the exhaust before the first O2 sensor. I also replaced one O2 sensor so that and the bypass lines cleared the check engine for awhile. Now I am getting both SAI codes as above but with two other readings: one says an MAF problem and another that says there is not enough air volume. One of the things my mechanic mentioned is there is a canister that supplies air to the SAI system that sometimes cracks. I am on the road and they are looking to see which problem is the real problem so now I need to have them make sure all the hoses are good.

99three · 08-04-2009, 11:12 PM

It's not the hoses since I triple checked them after the valve installation. It's surprising to see so much people experiencing the same issue I am. This seems to be more of a regular occurrence now that our VRAM cars are getting up in age/mileage. Where are the SAI experts?

AOW162435 · 08-04-2009, 11:25 PM

Quote:

Originally Posted by Gary Perry

One of the things my mechanic mentioned is there is a canister that supplies air to the SAI system that sometimes cracks.

Hmm. There is a black plastic vacuum canister affixed to the driver's side intake housing, but I thought the SAI system (regardless of year) draws its air from the rear of the airbox via a rubber hose?

Andreas

Gary Perry · 08-05-2009, 12:15 AM

From the description I was given it has something with the SAI system. What my shop did was re-plumb lines from the SAI air pump and they indicated that the vacuum canister is used to store air. I have to look at my PET when I get back so I can see what they are talking about.

SwayBar · 08-05-2009, 08:33 AM

Quote:

Originally Posted by mlucas70

What would interest me is where is the sensor that reads and monitors the air injection which decides that air isnt flowing. If it is the O2 sensors, then you would get a different error code.

With the engine running, the O2 sensor sends back a voltage to the computer. While the SAI pump is running, the voltage from the O2 sensor should fall within a certain leaner-range. If it does not, an error will be thrown related to the SAI. As you noted, there is nothing wrong with the O2 sensor, thus no O2-related errors.

mlucas70 · 08-05-2009, 08:57 AM

So what measures the air flow/blockage in the SAI ports to throw the P0410 code ?

Cheers

Martin

08-02-2009, 10:06 PM	#1
99three Addict Rennlist Member Join Date: Nov 2006 Location: Toronto Posts: 1,204	Not another SAI question... Does the CEL indicating the SAI code come on while normally driving, after it's fully warmed up, or while secondary air pump is running? __________________ Serf 96 993 Polar Silver - BBS RS-GT, Fabspeed 200 Cell Cats, Fabspeed Maxflow mufflers, Schnell Tips, Bilstein PSS9, Heated Factory Sport Seats, Carrera Cup Intake, Schnell Strut Brace, HID's, Clear corners, RS Shifter, RS Transmission mount, Gerts Protection Bar. DIY website: www.pcarworkshop.com

08-02-2009, 10:39 PM	#2
chris walrod Guru Lifetime Rennlist Member Rennlist Small Business Sponsor Join Date: Aug 2001 Location: yorba linda, ca Posts: 13,725	Typically takes two drive cycles from cold starts to trigger and store the code. __________________ Is this a great place or what? Chris 97 993 twin http://www.swiftengineering.com/ Cool Video Latest FN News

08-03-2009, 09:37 AM	#3
Deadeye Addict Rennlist Member Join Date: Sep 2007 Location: S.E. Mass Posts: 276	Mine comes back randomly300 to 500 miles after I clear it. I don't recall it ever coming on during those precious two minutes at cold start. __________________ Dennis '96 C2 cab triple black

08-03-2009, 07:01 PM	#4
99three Addict Rennlist Member Join Date: Nov 2006 Location: Toronto Posts: 1,204	So if I understand this correctly the computer stores two previous SAI codes, then at any time after a cold start up the CEL will light up (in my case it was well warmed up on the freeway going 100, bang...CEL). Is that how it works or could it be attributed to something else since I just replaced the SAI valve? __________________ Serf 96 993 Polar Silver - BBS RS-GT, Fabspeed 200 Cell Cats, Fabspeed Maxflow mufflers, Schnell Tips, Bilstein PSS9, Heated Factory Sport Seats, Carrera Cup Intake, Schnell Strut Brace, HID's, Clear corners, RS Shifter, RS Transmission mount, Gerts Protection Bar. DIY website: www.pcarworkshop.com

08-03-2009, 08:39 PM	#5
Deadeye Addict Rennlist Member Join Date: Sep 2007 Location: S.E. Mass Posts: 276	Could be SAI. You need to read the code(s) to know for sure. __________________ Dennis '96 C2 cab triple black

08-03-2009, 09:49 PM	#6
99three Addict Rennlist Member Join Date: Nov 2006 Location: Toronto Posts: 1,204	I used the Snap On code reader - P0410 code. SAI for sure. __________________ Serf 96 993 Polar Silver - BBS RS-GT, Fabspeed 200 Cell Cats, Fabspeed Maxflow mufflers, Schnell Tips, Bilstein PSS9, Heated Factory Sport Seats, Carrera Cup Intake, Schnell Strut Brace, HID's, Clear corners, RS Shifter, RS Transmission mount, Gerts Protection Bar. DIY website: www.pcarworkshop.com

08-04-2009, 12:21 AM	#7
tigerrat Addict Rennlist Member Join Date: Mar 2004 Location: Houston Posts: 58	Hmmm, if you just replaced the valve, I would double check that small, sneaky vacuum hose that attaches to the other check valve that is on the ~ 3/4" hose just above the SAI valve. It is short, hard to see and pops off when you pull the SAI valve. It bit me and I wasn't the first and I bet not the last. Ken __________________ Ken in Houston 88 911 Coupe 98 C2S Coupe

08-04-2009, 04:14 AM	#8
mlucas70 User Join Date: Jul 2008 Location: Germany Posts: 5	But wouldnt that trip both codes ? P0410 and P0411 (left and right bank). I too have just had the Check Valve replaced and experience exactly the same issue as 99three. The CEL goes on at the most peculiar time (on the autobahn at 80mph, in town at traffic lights) etc etc. Indeed it seems to be just the time when probably the readyness codes are about to set and then throws the CEL. I get the all too famous P0410 and clear it with my reader, usually comes on between 30 and 70 miles again. I always understood that the vacuum hose triggered both codes simultaneously. I have now read a great deal about the SAI, the ins and outs, the do's and dont's, the dreads and fears. What would interest me is where is the sensor that reads and monitors the air injection which decides that air isnt flowing. If it is the O2 sensors, then you would get a different error code. Changing the Check Valve in my case hasnt really done anything..... Martin

08-04-2009, 05:56 AM	#9
JStuart Addict Rennlist Member Join Date: Dec 2006 Location: Bellevue, WA Posts: 118	Same thing here...very random...both banks. I've had it go off 2x in a day...then nothing for months. I was told that it was 10...not 2 cycles. Always happens hot. __________________ 97 C4S Glacier White 69 280SL Silver...sold 04 EB Expedition

08-04-2009, 10:13 PM	#10
Gary Perry User Join Date: Jan 2003 Location: Phoenix, AZ Posts: 30	Going through this right now. My independent shop plumbed bypass lines from the air pump down to the exhaust before the first O2 sensor. I also replaced one O2 sensor so that and the bypass lines cleared the check engine for awhile. Now I am getting both SAI codes as above but with two other readings: one says an MAF problem and another that says there is not enough air volume. One of the things my mechanic mentioned is there is a canister that supplies air to the SAI system that sometimes cracks. I am on the road and they are looking to see which problem is the real problem so now I need to have them make sure all the hoses are good.

08-04-2009, 11:12 PM	#11
99three Addict Rennlist Member Join Date: Nov 2006 Location: Toronto Posts: 1,204	It's not the hoses since I triple checked them after the valve installation. It's surprising to see so much people experiencing the same issue I am. This seems to be more of a regular occurrence now that our VRAM cars are getting up in age/mileage. Where are the SAI experts? __________________ Serf 96 993 Polar Silver - BBS RS-GT, Fabspeed 200 Cell Cats, Fabspeed Maxflow mufflers, Schnell Tips, Bilstein PSS9, Heated Factory Sport Seats, Carrera Cup Intake, Schnell Strut Brace, HID's, Clear corners, RS Shifter, RS Transmission mount, Gerts Protection Bar. DIY website: www.pcarworkshop.com

08-05-2009, 12:15 AM	#13
Gary Perry User Join Date: Jan 2003 Location: Phoenix, AZ Posts: 30	From the description I was given it has something with the SAI system. What my shop did was re-plumb lines from the SAI air pump and they indicated that the vacuum canister is used to store air. I have to look at my PET when I get back so I can see what they are talking about.

08-05-2009, 08:57 AM	#15
mlucas70 User Join Date: Jul 2008 Location: Germany Posts: 5	So what measures the air flow/blockage in the SAI ports to throw the P0410 code ? Cheers Martin