Fix Code P0491 secondary air injection pump insufficient flow. 2009 VW Jetta 2.5L.

$59 secondary air pump aftermarket with free returns ebay.us/yiPA9p
$74.95 secondary air system combination valve. ebay.us/ijfjIX
these two are the most common cause of this code that is seen in the work manuals and forums.
if it's not these two parts that are causing your problem is either going to be the pressure pipe or pressure sensor or a wiring problem the O2 sensor or very rarely your map sensor.
Before you PURCHASE EITHER OF THESE I recommend running through the test procedure that I have in the video to see if these two work if they don't the ones I have listed above or the best cheapest I could find.
I've been struggling with this code for quite a while now I finally figured out the problem one of the problems a bad secondary air pump and blown fuse.
I just wanted to share my results, and some of the techniques I used to figure it out so hopefully it will help somebody out there diagnosis this problem faster.
although I still have a check engine light after this I did fix some of my problems.
I will update if I ever get this thing figured out #$_#@_+_$$!!

[@insanelogic9955]

THANK YOU! I’ve been trying to find a way to test the pump while it’s in the car or just show me where it is in the older Jettas but I couldn’t find anything until this and you explained it all very well, thank you!

[@stephengoad3091]

You're welcome Happy I could help. If you could please like and share the video.

[@stephengoad3091]

You welcome happy I could help.

[@helloeveryone7201]

You got to love German engineering:)

[@RE-vu4fb]

Awesome overview. Thank you for sharing

[@dcartellone2659]

Thank for sharing your knowledge..question, I got the up graded senor with the pipe..whats the easiest way to replace this.was told had to remove the throttle body for clearens. What tools will I need. Can seem to find out.

[@stephengoad3091]

The tools you don't need to do the job will be t25 torque spec T30 torx bit a bit socket for quarter inch drive ratchet and the ratchet and a pair of pliers that are big enough to remove the intake hose clamp. First remove the engine cover, you'll have to own you two screws on the main air intake at the front of the engine compartment and the one hose clamp after that grab around the edge starting at the side near the belt and pull up on the engine cover it hasn't been removed it will probably be very stuck I'll have to wiggle it up and down quite a bit I haven't obvious from its rubber grommets. After that you will have to remove the second hose clamp connected to the throttle body and the two hoses connected to the intake hose There's two tabs on each of those little pipes you have to squeeze and it will pop down and away, sometimes they are fragile and very stuck. You may even have to get the pair of pliers and easily press the two tabs in to have it slipped off. Then disconnect the wire connected to the throttle body it'll be on the bottom side the easiest way to do this is push in on the wire connector there's a little tapping pole back on and then the whole thing just slide off After that remove the four screws holding on the throttle body there will be a rubber o ring on the back side of the throttle body it is a good idea to replace it but not necessary unless it tears. Once the throttle body is removed you will have access to get down and disconnect the pressure tube off the top of the pump, it'll be exactly the same technique you used the earlier too small pipes on both ends. Then disconnect the pressure sensor using the same technique you used for the connector on the bottom of the throttle body. When you have it off it is a good idea to check the pump and the combination valve on the back side of the engine for water, if there is a lot of water in the pump or in the combination valve the combination valve may be going bad and a combination valve is going bad there should be a lot of soot as well in there. You're also be a small hose holding on the front side of the you'll need a flat head screwdriver to put down in between there and the top will flip away from the pipe it works kind of like a zip tie it's got little prongs on one side that snap and hold it together that's where you need to put the screwdriver in to pry it back and away from those. Then it will just be everything in reverse to put it back together. Hopefully this helps. Also consider subscribing I need all the subscribers I can get right now.

[@stephengoad3091]

Is actually the tools you will need not don't need spell check kicked in.

[@dcartellone2659]

@@stephengoad3091 THANK YOU so much, This job seemed alittle intimidating until you really broke it all down for me, dealer was looking for 1,200-1,400 for this hose job. Thank you again my friend.

[@stephengoad3091]

@@dcartellone2659 Your welcome I'm hope I could help you save all that money. Yeah most mechanic shops nowadays are just a ripoff.

[@thecrittergitter7576]

Ok, 07 2.5 wabbit 5spd stick. 2ndary air pump is running like a vacuum full-time. I found the hoses to the pump compromised, replaced both hoses. Replaced pump, replaced solenoid valve, and swapped the 100amp fuses to see if that was the issue. I even replaced the MAP sensor under the throttle body. I cleaned the throttle body while I was at it. I have looked for this SAI sensor but have never found it, it's supposed to be on one of the tubes, but there's nothing. Also, I am the one and only owner. I did find a video about the SAI and MAP sensors being physically identical. However, they are not one has to be sure that the right part number is in the right location. Any help with this situation is greatly appreciated.

[@stephengoad3091]

To the pressure sensor for the pump should be in between the pump and the combi valve on the back of the engine should be right beside the battery box, I haven't even seen a tube without the hole for the sensor so I'm not sure what you have there. Should be a two prong or three prong plug that comes show the wiring harness going across the engine that's where you should find the two or three prong plug. The only thing that I can think of is if the ground sensor wire that runs from the computer to the relay has shorted out that would kick the relay on all time. The computer is only supposed to ground out the terminal for about 20 to 30 seconds on cold start you can try testing if you have a ground all the time on that relay if so there's probably going to be a problem with the ground wire shorted out or the computer. If it's the computer you might want to think about a delete for the secondary air pump system if you're in a state that could allow that to happen. The pressure switch on the tube if it yours does have it I don't think it's going to be the issue cuz all it does is says that there is a sufficient pressure in the system it doesn't kick on and off the pump. So what I'll do is first start by just trying the ignition on but leave the engine off check your power coming to the relay and then check your ground from the other terminal and make sure that it's not grounded I believe these vehicles work on a grounding system where the computer grounds out whatever system it wants to turn on so I think the hot wire will be hot whenever the key is on only the ground wire gets turned on and off. Hopefully this helps.

[@bsagar86]

I have the same problem. I can’t find the sai sensor did you?

[@genarin84]

I got the same issiue I did tje same new sai new convi new sensors i clean the pipe next to tha convi it was a lot of carbon inside but the check engine light still ON

[@stephengoad3091]

There could be carbon in be small home in the exhaust manifold, sometimes it can get filled with carbon and restrict airflow. Also it could be your Cadillac conversion getting stopped up that can sometimes cause it to show this code. You did replace the actual air pump correct. Also another good test would be do a leak test on the system by getting a smoke test. It actually took me about 2 to 3 times to get the check engine light off. One thing to remember all pumps are not built equally I want to Eevee pumps and one had a massive leak around the plastic housing and the other one didn't put out enough volume for the system to turn the switch on. Hope you get the light fixed, trying to chase these codes down can be a real pain not to mention expensive as well.

[@guestlisttonight8337]

Do you happen to know the part number for the hose that goes from the combination valve to the pump? I want to make sure i get the upgraded sensor and hose for the mk5 2.5 engine on a 2007 jetta. Thanks

[@stephengoad3091]

Here is the original part for sale on eBay, this link will take you directly to the page and we'll have all the information there this is a genuine part from Volkswagen. ebay.us/chjWis Also this is about the cheapest original part I could find.

[@guestlisttonight8337]

@@stephengoad3091 thank you so much.

[@alexmartinez-wp2oh]

How.do you bench test it with the red n green wire to a battery?

[@stephengoad3091]

Yes that is correct. There shouldn't be any squealing or chirping from the motor and there should be a very high RPM sound with a lot of air from the output side.

[@themachine8009]

Do Toyota’s or Hondas have that system? Or is this exclusively for VWs and Audis?

[@stephengoad3091]

No it's not exclusive most vehicles have either anxiety air pump are the engine will run faster for about a minute when you first crank it on the only on cold starts. All this to for is to heat up the Cadillac converter fast. You really have to look into your in person and on the internet do you find out if I wish system.

[@naomicastillo2000]

I have code P2432, I followed your video replaced the whole second air injector but I am still showing check engine with the same code, any advice? Thanks!

[@stephengoad3091]

Did you check the pressure sensor on a small tube and make sure it was? Also I have heard with high mileage engines the tube on the back of the engine sometimes gets blonde up and slows the flow there. I'm not sure how you really check that though. Could also be O2 or a stopped up catalytic converter. If you haven't changed out the sensor yet I would do that first it's only a few dollars sensor off eBay. Also they have a whole update kit with sensor in it like I talked about in the video. I hope something of this will put you in the right direction, also did you do a smoke test to make sure you didn't have any leaks?

[@alfonsogonzalez2099]

Mine is an 08 amd both relays say 370 instead of 100 should i put 100s instead or will that mess with the cars computer?

[@stephengoad3091]

It's a 370 relays are original to the car then definitely reuse a 370 relay. If you have two 370 did you switch him and see what. If you don't I probably go to your local automotive shop or buy one off the internet and replace it. But really you could just jump the two wires to see if the pump motor comes on. Just make sure that the relay is for the secondary air pump. If you don't feel comfortable with it don't do it and let him mechanic antler, I just don't want you to burn up on your car. Also if you do cross over the two 12-volt wires all you have to do is just touch it for a second and it should do something. If nothing happens take the wire off immediately. Good luck I hope you can figure it out.

[@alfonsogonzalez2099]

You should make a video on how to test this specific pump using an extra car battery and what tools you are using youre very good with details in your videos

[@stephengoad3091]

If you have the battery in the vehicle and a short heavy gauge piece of wire all you got to do is jump from the Hotpoint 12v in on the relay to the other side of the relay or fuse the relay on that side is always hot with 12 volts no matter if the vehicle is turned on or off. So you can run that test with the battery in the vehicle with key off. If you do 8 minutes in The video I discuss how the test the pump when it's in the vehicle. I hope you you can get this fixed and cut the check engine light, I know some states won't allow it to pass if it isn't.

[@miguelgotgame219]

Will this work for code P0411

[@stephengoad3091]

YES it should be one of the things that I talk about in the video. It should be either the air pump or the line going to the combination valve. I definitely check and see if on cold starts if the pump runs for a few seconds. If not I would jump wire it like I do in the video make sure that it is running if not you will have to replace it.

[@thecrittergitter7576]

Unlike the video but how the heck did you get the pump out?

[@stephengoad3091]

Well to tell you that secret you're going to have to LIKE the video. JUST KIDDING the easiest way to get the pump out of that little hole is to take the four T25 bolts out of the throttle body she's the throttle body on top of the intake you should be able to get to one of the top nuts on the back side of the river Mount that holds the pump in position for the other one you may have to use two 8-in quarter inch drive extensions together and go across from the belt side underneath the intake and use your other hand to guide it onto the nut on the back side of the rubber wallet those nuts should be a 10 mm. You shouldn't have to worry about the bottom one mount it should just slide right up off the bottom mount. Once you get the pump out then you can either take off that lower mount or at least inspect it to make sure it's okay. Well I hope this helped, also since you unlike the video what would you suggest to make it better?

[@alfonsogonzalez2099]

Mine is the same but my code is p0418

[@stephengoad3091]

Yeah so believe this code is going to be for electrical. I'd start off by checking both fuses and the relay there should be one small I believe 10 amp fuse and 1 Big Orange fuse in the back of the box and the relay. I believe you can take out the relay and change it for another and you can check it that way. If both fuses and relays seem to be good, then try jumping the power in the relay like I did on the video and see if the you can hear the fan motor come on. If the fan motor isn't running or it sounds slow or doesn't spin good, then it'll probably be your air pump motor has went bad. Which of these motors is a normal occurrence, and will have to be replaced. You can also unplug the wire down at the fan motor if a mother does not come and you can use a test light to make sure you got power down there at the fan before you disassemble everything to get the pump out. If you got power and the fans not going the pump is probably your issue. And before you disassemble everything Make sure you check your wiring and your ground locations these cars are also known for bad grounds. Well I hope something in here helps but most of the comments I got on this video was on the pump motor burning out and had to be replaced. A cheap pump will cost you approximately $70 to $90 dollars. I believe there is a link in the description

[@alfonsogonzalez2099]

Daaaaam ahhaha thats a lot before i start here where i am im getting used to going to junkyards and i must say that those parts are not perfect but some work just fine so i bought the air pump and switched it changed the hoses that connect to the valve near the back which is called i believe the combination valve the only issue is that i still have the check engine light on and the pump only seems to turn on at coldstarts so im guessing ill have to wait till the next morning to be able to hear the motor if it were to spin...now my only last chance would be to change the combination valve right? Or maybe i should just take my car to you 🤔

[@jwithapen]

Is the pump in the same location in a VW beetle