Secondary Air Injection System on BMW E46 330XI (Code P0491/P0492)

[@dave95b86]

Hands down the best video I’ve found covering how to test and fix P0491/P0492 codes. I have an E39 2002 530i.Thanks for being so detailed.

[@GearSpec]

Thank you for your nice comment, it means a lot 😊😊

[@stanleyplock1181]

2004 325i Behind the intake manifold is the electrically actuated valve that controls the main valve. The hoses get hot and brittle. It's extremely difficult to access them. Especially the ones that go to the intake manifold vacuum ports. They are way back under the manifold. You can see them with a somewhat large mirror. But it's extremely difficult to maneuver with a reverse mirror image. You can get an exacto-knife to cut off the broken section. (With extreme difficulty). To install the new hose, I ran a pointed coat hanger inside the new line and positioned it Inside the metal port tube. Then slid the vacuum hose down along the outside of the coat hanger. I lubricated the inside of the line with WD 40. (Or any lubricant)

[@GearSpec]

That’s great information, thank you for the insight 😊

[@alovely4478]

great job i like that you explained the names of each part you dealt with (:

[@GearSpec]

Amber Loveless thank you, I appreciate it 😊

[@HfxpokerPlr]

Very detailed video. Now to get me a bmw and ill be all set

[@GearSpec]

HFXpokerPLR haha thank you 😊

[@nammiknamo9741]

Well done bro, explained in details, thank you for sharing 😊👍

[@GearSpec]

Nammik Namo glad you found it helpful 😊

[@indritbanigs1501]

Nicely done bro, very informative video 👍

[@GearSpec]

BMW E90 thank you 😊

[@cjyt6491]

Excellent video

[@GearSpec]

Thank you 😊

[@ajibaby2217]

Great video and explanation. Much appreciated. Thank you. I have a 328i with p1421 and 1423 code. What might be the reason for that. Any assistance is appreciated.

[@ronniepainter7533]

Great video. Now how about a video on replacing the Valve on the back of engine.

[@GearSpec]

Ronnie Painter sounds like a plan 😊 I just don’t know how much I can record back there because of the tight space lol

[@ronniepainter7533]

Gear Spec I know that’s right.

[@GearSpec]

It’s doable anyways lol

[@andrewbruix6721]

Very good detailed video, thanks for making this.

[@GearSpec]

Andrew Bruix You are welcome, glad it was helpful 😊

[@tinae4636]

Great video. ⚒

[@GearSpec]

Tina E46 thank you 😊

[@MechaniclifeJDM]

Reasons for secondary air not to work. Engine not cold Lazy O2 sensors-upstream Faulty relay Shorted wiring Faulty fan Broken fan blade Broken fan to vacuum valve hose Broken vacuum hard line or hose Insufficient manifold vacuum Failed vacuum valve Plugged ports in cylinder head Failed vacuum solenoid on back of manifold Incorrect hose connections to the vacuum solenoid (one vents to atmosphere when de-energized) Those are the main ones I found lazy old O2 sensor, bank 1 upstream no other codes for that sensor, just that secondary air monitor would not set

[@howlingmedia4354]

If I turn the key on, would there still be some kind of flow of current showing up on the test light?

[@valerianpantsulia1730]

After all..........God Dammit BMW brand///// Nice video and Good job, it was very interesting. Thank you ///////////////////

[@GearSpec]

Glad to jave helped 😊 Regarding BMW, at least we enjoy driving them, even though expensive to maintain 😊

[@youonlyliveonce2556]

Does a bad air injection pump ruin the catalytic converter ?

[@GearSpec]

No it won’t to the point of being concerned, but it will pollute the environment, because that pump only works for 90seconds

[@ВиталийНик-в9л]

Привет . А что даёт сигнал на реле , что бы оно включило насос ?

[@javierpanameno7005]

hello ... I have a problem with my bmw ... and I think it is electric ... when I did the test on the connector ... they both turned on the same ... not as presented in the video ... any idea ?

[@GearSpec]

Javier Panameño if you are lucky then you can just open up the relay and inspect it, clean it. If not fixable then you need a new relay and that should fix your problem 👍

[@jtaylor4027]

Why don't you show where the small hose connects between the engine and firewall and the fuse in the ebox inside the small black box that has (4) 30 amp and (1) 20 amp?

[@GearSpec]

John Taylor thanks for your comment, it’s a really tight area over there especially to record, but if you follow the small hose it will take you to where it connects. This job is more of hand feeling because there’s not much you can see

[@1072sixela]

I have a question please, I have an E46 M54 2,5, as long as this pumbe works takes my car super gas on, rather the cold start valve, speed about 1000 rpm, as soon as the speed at 650 he takes bad gas and goes Often out, without gas is difficult to drive, i chainge the CCV........... sry for my bad englisch

[@GearSpec]

1072sixela sorry for the late reply, I had missed your comment. Hope you have it fixed by now. I don’t think your problem is related to secondary air injection system however I would recommend to check the vacuum line and valve which are located respectively around your engine block and behind the engine. I would say check your ccv system, even though you have it changed. Make sure the timing is correct and all the engine sensors are in working condition. Let me know if you have any other questions! And good luck! 😊

[@ovidiurisco1251]

Hi ,i have a Bmw e46 318 i can my car run without it ?

[@GearSpec]

Yes it can, but if you have emission test than you need to replace it because you can’t pass the test.

[@donshilo2024]

I have a x3 I did the test and no air coming out does it works all the time or is on and off?

[@GearSpec]

It works only the first 90 sec on a cold start after that it doesn’t work anymore until the next cold start

[@stavi82]

huh, i'm only getting P0491, not P0492...

[@andypicasso185]

I have a e39 with the same codes would it make my car feel sluggish when accelerating?

[@GearSpec]

Andy Picasso no it shouldn’t, these codes are only for smoke and environmental pollution

[@andypicasso185]

Gear Spec ok first time driving these cars maybe it’s just not as fast as I thought lol thank you

[@andypicasso185]

Gear Spec but basically this code isn’t anything to worry abt right away it won’t harm anything right so I can wait till emissions comes

[@GearSpec]

Andy Picasso it’s nothing to worry about

[@omarceja321]

On my e46 m3 it turns on but only for 2 seconds at most. Anyone one else run into this issue?

[@GundamDRose]

They only turn on for a few seconds during initial start up 👍🏾

[@kapilricky]

👍👍

[@ericgon46]

Any ideas on what might be the cause of a p0414 error code? The code says "secondary air injection switching valve 'A' circuit shorted"

[@GearSpec]

Eric Gonzalez So you get the P0414 code? Did you check the 50 amp fuse, and know the relay is ok? Most likely is the switch at the back of the engine. You can jumper power to the air pump and turn it on so you know it is ok, just like I showed you in the video. The switch is hanging under the back side of the air plenum/manifold and is hard to spot even if you remove the guards around the brake master cylinder area. Just follow the vacuum line to it and maybe a mirror and as much light as you can throw on the subject without the light itself obstructing your view. You would more easily notice that there would be a connector without a home in that area. That is easier to see than the switch it plugs into. The switch is mounted in a rubber hanger that slips over a sheet metal bracket to hang it under the manifold. You should also check that the vacuum line to the valve on the front of the head is ok, and you can follow the vacuum line all the way to the switch under the manifold to confirm you're looking at the right thing. Good luck!😊

[@ericgon46]

Gear Spec Hey so the issue that I figured out years ago was that non return check valve, the black and white valve behind the manifold was flipped. I had removed the intake manifold when I replaced my ccv/pcv and installed the check valve backwards.

[@ericgon46]

Gear Spec 2 years later and now I’m getting both p0491 p0492 so I’m going to try to test the air pump to see if it’s functional

[@Yophillips3272]

My brothers car made a loud whistle noise randomly, I wonder if it had something to do with this dumb thing.

[@GearSpec]

Toad Phillips You are not wrong, mine made a loud whistle noise too, but that whistle noise it’s not just the secondary air pump. Just check it out with a piece of paper and you will know. Good luck 👍

[@jtaylor4027]

As I understand the pump comes on at cold starts only for less than a minute to cool the catalytic converters and blow the fumes out of the exhaust.

[@jameslimon3137]

BMW you have to do so much crap just to get to something, this car sucks

[@GearSpec]

I agree with you, and there is no need for that. They have a unique twisted way of doing things. But once you are familiar with it, it just becomes normal to you too 😊

[@valerianpantsulia1730]

Goddammit BMW BMW they should bankruptcy they deserve it because they make it too many people suffering and lost a lot of money ........Goddammit BMW........

[@GearSpec]

I’m sorry to hear that. I hope that you and your loved ones are ok. Regarding money, that’s a choice we make and it’s easy fixable 😊

[@markatiarsed332]

👍👍👍