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I'm not 100% clear on how you're describing they system.

But I do know that the "mechanic in a can" is a quick and easy way to attempt to resolve the problem before I go digging any further. It's also cheap, so no harm there. If it doesn't work then I may have to put more time into the car. Time is at a premium for me these days, so its worth a shot.

BTW, I don't have a code reader. I just go to AZ to get the codes read. If I have to, I'll set up PASoft so I can get more information when this stuff happens.

My car has 175k miles, so I'm guessing I'll be seeing more and more SES lights as the car reaches and surpasses 200k. So if I want to keep it on the road that may be a sound investment.

Is it only the pre-cat o2 sensors that might be the problem? Cuz the postcat sensors are a PITA and probably even worse on an XI.

Reading through your other thread, sounds like this could be a real PITA. May just be time to trade the car in if replacement pre-cat o2 sensors dont solve he problem.
If you are talking about an xi, then the SAP does not have the input MAF, is the standard SAP system with a single output hose, I know the system very well.

The system runs for up to 90 seconds on cold start or until the engine temp reaches 100F, which ever comes first.

"Mechanic in a can" will not do anything, trust me.

PA Soft will not do what is need, PA Soft rarely supports live DME data as well. A smart phone App and interface for under $30 is all that is needed.

If the issue is with lazy O2 sensors, it will be only the pre-cat sensors that report the SAP function.

But there are other problem areas for the SAP to no work properly as well.

P0491/P0492 are the typical codes associated with the early, non MAF based SAP system which the xi should have.

The SAP system is actually the easiest system to sort out on these cars, not worth selling the car over this issue.

I unfortunately know more about this than I care to share.
 

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Secondary air pump problems

I completed the treatment with seafome today in the morning while the car was still cold. The treatment worked and the service engine light turned off by itself. I had this light on for last 2 years. I knew everything else worked fine in the SAP system. Thank you again for the instructions. It worked like a charm for me.
Do not get scared with white smoke coming feom the muffler.
 

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Apologize foe reviving this thread, but I needed some advice. I have read through this entire thread and other related threads but din't fine answer.

I am now getting really fed up of the P0491 and P0491 Codes (Secondary Air Injetection Bank 1, Bank 2) codes on my 2001 325xi. Bothering me for more than a year now.

I just replaced the Air pump (it had stopped) and the check valve. The Air is now being pumped in by the SAP, but I still get the codes after resetting the CEL.
Yesterday I did the Seafoam trick to see if that clears out something, but I dint see any thick smoke and the Seafoam remained in the hose (I cold started the Car).

When i saw the Seafoam remain the hose and the fact that the Pump is working, I am concerned that the Seafoam would definitely be sprayed back into the pump when i cold start the car.
Is it possible for the Seafoam to damage the SEP? Or is it harmless?
I guess I would have to take apart the whole Vacuum line now.
 

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Have you replaced your vacuum lines, all 3 of them?
If so then you have a bad valve or a bad switch. I am thinking however that you simply have not replace all 3 of the vacuum lines and the system may work just fine.

The sea foam should not have to be used, and only as a last resort when making sure all the vacuum lines and the valve are working, by pulling the valve off the header and making sure the SAP is blowing air through it on cold start.
 

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Forget the Seafoam will not resolve the problem. If it helps, it means the O2 sensors were carboned up, but ANY E46 SHOULD NOT still have the original pre-Cat O2 sensors still installed. If the Seafoam actually worked for anyone chances are they have other deeper problems that will reappear, but everyone seems to want a $10 "Mechanic In The Can" solution. Trust me, it is not a permanent fix regardless of what anyone claims.

In addition to all the SAP system components needing to be functional, the pre-Cat O2 sensors are key for properly monitoring the SAP airflow.

SAP system is actually pretty easy to get sorted out.

You need to READ ALL of these links carefully.

You will NEED an OBDII smart phone/tablet App and interface as well.

Suggest OBDFusion and the correct OBDII adapter, Bluetooth for Android and Wifi for iProducts.

You need to READ ALL of these links carefully. More than you care to learn, but will pretty much cover every aspect of the SAP system.

http://forum.e46fanatics.com/showthread.php?t=1041726

http://forum.e46fanatics.com/showthread.php?t=1023149

http://forum.e46fanatics.com/showthread.php?t=965526

http://forum.e46fanatics.com/showthread.php?t=1052605

http://forum.e46fanatics.com/showthread.php?t=1074847

http://forum.e46fanatics.com/showthread.php?t=106959

http://forum.e46fanatics.com/showthread.php?t=1074847

http://forum.e46fanatics.com/showthread.php?t=106959

http://forum.e46fanatics.com/showthread.php?t=1078986
 

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Forget the Seafoam will not resolve the problem. If it helps, it means the O2 sensors were carboned up, but ANY E46 SHOULD NOT still have the original pre-Cat O2 sensors still installed. If the Seafoam actually worked for anyone chances are they have other deeper problems that will reappear, but everyone seems to want a $10 "Mechanic In The Can" solution. Trust me, it is not a permanent fix regardless of what anyone claims.
Yeah well, the $10 "mechanic in a bottle " has already bought me 9+ months of SEL free driving...worth it.

My car has almost 200k miles and isn't worth much..maybe 2-3k or 4 if I'm lucky. A set of O2 sensors represents a substantial percentage of the total value of the car.

Not to mention, it took me all of 10 minutes to "fix" this issue with sea foam. If the SEL light comes on in a month or a year, I've already won.
 

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So I read this and a little bit still confused after having the check valve codes , I replaced both the hose and the valve. I actually had to buy 2 valves because the first one I ordered was a cheap Chinese crap that did not properly clip to the hose causing the hose constantly fall off so I had to get the genuine valve.
Despite the new valve the hose the service engine light is still ON!
I did first SeaFoam treatment this early morning at the start. There were clouds of white smoke all over my neighborhood. I almost got choked on all this carbon dioxide. The fricking light is still ON!
I know my air pump works because I can hear it at the start, I know I got new secondary valve and hose, and i did read codes saying it is the fricking "back pressure secondary check valve" so what is the issue?
I also have no vacum lines running to my check valve because my car is 2004 and it uses the second generation valve. What coul it be?

Having said that and having read the entire post with all its contents, will it be right to conclude that it is the pre cat O2 sensor? Or should I open the plastic cover to examine the alginate vacum lines that I doubt I even have?
 

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So I read this and a little bit still confused after having the check valve codes , I replaced both the hose and the valve. I actually had to buy 2 valves because the first one I ordered was a cheap Chinese crap that did not properly clip to the hose causing the hose constantly fall off so I had to get the genuine valve.
Despite the new valve the hose the service engine light is still ON!
I did first SeaFoam treatment this early morning at the start. There were clouds of white smoke all over my neighborhood. I almost got choked on all this carbon dioxide. The fricking light is still ON!
I know my air pump works because I can hear it at the start, I know I got new secondary valve and hose, and i did read codes saying it is the fricking "back pressure secondary check valve" so what is the issue?
I also have no vacum lines running to my check valve because my car is 2004 and it uses the second generation valve. What coul it be?

Having said that and having read the entire post with all its contents, will it be right to conclude that it is the pre cat O2 sensor? Or should I open the plastic cover to examine the alginate vacum lines that I doubt I even have?
You have a 2004 model year vehicle so your car should have the SAP system with no vacuum line to the Kombi valve on the front of the cylinder head. The SAP system should have a Input MAF to measure the SAP air flow. The O2 sensors should be 5 wire Wideband O2 sensors which do not monitor the SAP system. The SAP pump should have 2 hoses with quick release plastic clamps.

You need to post EXACT Pxxxx codes and read this thread - http://forum.e46fanatics.com/showthread.php?t=965526&highlight=priceless

Suggest you also take a picture of the SAP pump with the hoses and try to get the Kombi valve is the picture and post it back here. It will help understand what we are really working with. I assume your SAP and valve looks like the one in the link above?
 

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Scanned the codes and got the MAF code. P0175 P0172 P0411 P0174 P0171 I guess thus is one of those times when you replace one issue the next issue appears right after.
So here is the deal, the MAF for for the SAP is likely bad, not the engine MAF. There are 2 different MAF's on your car. Make sure you pay close attention to my link above.

Other things that can cause the SAP MAF error, SAP pump turning too slow due to Voltage drop or tight bearing, air restriction, but the problem is most likely the SAP MAF.

So here is what you need to do.

Go to www.bmwgm5.com and look up the SAP MAF part number, then use this link to find the best pricing www.bmwpnpc.com

For the other codes, not sure what tool was used, the readout is likely wrong. The car probably only has Lean codes.

You need your OWN OBDII tool.

You want the OBDFusion App and interface for $30 or less. Order the interface NOW! Trust me.

Android $3.99 App, interface around $12 for a total of about $16

http://www.amazon.com/Veepeak-Blueto...peak+bluetooth

iProducts $9.99 App, interface around $18 for a total of about $28

Amazon.com: Veepeak Mini WiFi OBD2 OBDII OBD II Scanner Scan Tool Adapter Check Engine Light Diagnostic Trouble Code Reader for iOS iPhone iPad and Android: Automotive

As for the Lean codes, most likely a vacuum leak.

Probably intake boots need to be replaced, also may have broken a CCV hose, the CCV and hoses probably need to be replaced as well.

Suggest you read my comments in this thread regarding Lean codes and misfires - http://forum.e46fanatics.com/showthread.php?p=16727145
 

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So here is the deal, the MAF for for the SAP is likely bad, not the engine MAF. There are 2 different MAF's on your car. Make sure you pay close attention to my link above.

Other things that can cause the SAP MAF error, SAP pump turning too slow due to Voltage drop or tight bearing, air restriction, but the problem is most likely the SAP MAF.

So here is what you need to do.

Go to www.bmwgm5.com and look up the SAP MAF part number, then use this link to find the best pricing www.bmwpnpc.com

For the other codes, not sure what tool was used, the readout is likely wrong. The car probably only has Lean codes.

You need your OWN OBDII tool.

You want the OBDFusion App and interface for $30 or less. Order the interface NOW! Trust me.

Android $3.99 App, interface around $12 for a total of about $16

http://www.amazon.com/Veepeak-Blueto...peak+bluetooth

iProducts $9.99 App, interface around $18 for a total of about $28

Amazon.com: Veepeak Mini WiFi OBD2 OBDII OBD II Scanner Scan Tool Adapter Check Engine Light Diagnostic Trouble Code Reader for iOS iPhone iPad and Android: Automotive

As for the Lean codes, most likely a vacuum leak.

Probably intake boots need to be replaced, also may have broken a CCV hose, the CCV and hoses probably need to be replaced as well.

Suggest you read my comments in this thread regarding Lean codes and misfires - http://forum.e46fanatics.com/showthread.php?p=16727145
Thanks I will be ordering the stuff .
 

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So here is the deal, the MAF for for the SAP is likely bad, not the engine MAF. There are 2 different MAF's on your car. Make sure you pay close attention to my link above.

Other things that can cause the SAP MAF error, SAP pump turning too slow due to Voltage drop or tight bearing, air restriction, but the problem is most likely the SAP MAF.

So here is what you need to do.

Go to www.bmwgm5.com and look up the SAP MAF part number, then use this link to find the best pricing www.bmwpnpc.com

For the other codes, not sure what tool was used, the readout is likely wrong. The car probably only has Lean codes.

You need your OWN OBDII tool.

You want the OBDFusion App and interface for $30 or less. Order the interface NOW! Trust me.

Android $3.99 App, interface around $12 for a total of about $16

http://www.amazon.com/Veepeak-Blueto...peak+bluetooth

iProducts $9.99 App, interface around $18 for a total of about $28

Amazon.com: Veepeak Mini WiFi OBD2 OBDII OBD II Scanner Scan Tool Adapter Check Engine Light Diagnostic Trouble Code Reader for iOS iPhone iPad and Android: Automotive

As for the Lean codes, most likely a vacuum leak.

Probably intake boots need to be replaced, also may have broken a CCV hose, the CCV and hoses probably need to be replaced as well.

Suggest you read my comments in this thread regarding Lean codes and misfires - http://forum.e46fanatics.com/showthread.php?p=16727145
I have replaced the secondary MAF as we thought it was the issues and to remind, this is the last part after the SUP pump brand new. Everything else is new and it did not solve the problem of p0411 and lean\ritch codes that I suspect linked to p0411.
Ive attempted to reboot the ECU by unplugging the negative terminal on the battery but it didn't work. The ses light came on as soon as I started the engine and the SUP pump run like crazy as ot did before for 5 sec and then turned off. Nothing changed after the replacement of the secondary MAF !

Another thing that I have noticed was that before I had the issues with the secondary air injection, I never heard the pump running like tgat. Now at cold starts it runs like a jet turbine, loud like a vacuum cleaner and then shuts off. Is that even normal?
It sounds like to those who are familiar with electronics if in your PC a cpu is bad at start all fans run at full speed because there is nothing controlling them. Could the full speed SUP pump run at the start mean that it is simply not controlled because the ECU still has the p0411 codes stored? If perhaps so, then how do I clear the codes? Thanks
 

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I will reply in more detail later but the fact the pump only runs for 5 seconds means there is an error. Either the pump is not moving enough air or the replacement SAP MAF is junk or there is a wiring problem.
 

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I will reply in more detail later but the fact the pump only runs for 5 seconds means there is an error. Either the pump is not moving enough air or the replacement SAP MAF is junk or there is a wiring problem.
Thanks, the pump itsself is the last part that is still old, I would hate to shop for one. The cheapest one I saw was $180 (after market).

The sensor (MAF) is actually genuine made in Germany part. It is not the BMW one, I think they are all made by 3rd party. Simens makes them. So I do not suspect it being the cause.
I need to examine the pump closely. To the first look it spinns freely and does get all 12 volts at start.
The only last thing is the Error. I am not sure about that. How could it be. Maybe the MAF filter is clogged. I am hitting the dead end with this and start to suspect unheard things that seem les likely to be the cause of the issue.
 

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Thanks, the pump itsself is the last part that is still old, I would hate to shop for one. The cheapest one I saw was $180 (after market).

The sensor (MAF) is actually genuine made in Germany part. It is not the BMW one, I think they are all made by 3rd party. Simens makes them. So I do not suspect it being the cause.
I need to examine the pump closely. To the first look it spinns freely and does get all 12 volts at start.
The only last thing is the Error. I am not sure about that. How could it be. Maybe the MAF filter is clogged. I am hitting the dead end with this and start to suspect unheard things that seem les likely to be the cause of the issue.
We have had a few of these MAF based SAP pumps actually have the impeller spin on the motor, so it sounds like it is running, which the motor is, but there is no air movement.

You need to disconnect the pump input hose and make sure the pump is actually sucking, if you disconnect the pump output, it may spin the impeller with no back pressure and fool you.
 

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We have had a few of these MAF based SAP pumps actually have the impeller spin on the motor, so it sounds like it is running, which the motor is, but there is no air movement.

You need to disconnect the pump input hose and make sure the pump is actually sucking, if you disconnect the pump output, it may spin the impeller with no back pressure and fool you.
You know what, you've just made a renaissance in my mind. It might well be the motor running without connection to the impeller. This might well be the case.
I am pulling the hose tomorrow morning to see if that is the case.
And this could also explain the high pitch noise since there is no load on the motor.
I am going to disassemble the pump if that is the case to see of at least something can be fixed. I saw some folks had success rebuilding these pumps.
 
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