[Birdmandoom]

I have a 2013 335 xdrive 166k miles and when the car is warm and I turn it on it shakes and it “gasps for air. During a cold start it doesn’t do it. I get the too lean and too rich code at the same time. I change the maf sensor and that didn’t help: so I have no idea what I could be. Any ideas? Thank you.

[thejeremyman9]

Super vague. We need actual codes, mileage, mods/tune if any, any recent service before the issue started, did it start suddenly one day or get worse over time, datalogs if you are tuned, etc etc. Otherwise we are just guessing.

If we are guessing, and you are getting both rich and lean codes, top of my list would be O2 sensor(s)

[Birdmandoom]

Originally Posted by thejeremyman9

Super vague. We need actual codes, mileage, mods/tune if any, any recent service before the issue started, did it start suddenly one day or get worse over time, datalogs if you are tuned, etc etc. Otherwise we are just guessing.

If we are guessing, and you are getting both rich and lean codes, top of my list would be O2 sensor(s)

It’s codes P0171 system too lean bank one
P0172 system to Rich bank 1
And P0440
No mods or tunes that I know off.
Any guess?

[weehe126]

Does it drive? Id guess a vacuum leak.

[Birdmandoom]

Originally Posted by weehe126

Does it drive? Id guess a vacuum leak.

Yes it drives fine. It’s just the start where it shakes and gasps for air for like 15 seconds then it normalizes.

[njdangelo]

Originally Posted by Birdmandoom

Yes it drives fine. It’s just the start where it shakes and gasps for air for like 15 seconds then it normalizes.

MAF or o2 sensor would be where i start looking

[weehe126]

Originally Posted by Birdmandoom

Yes it drives fine. It’s just the start where it shakes and gasps for air for like 15 seconds then it normalizes.

So no power loss, only happens when warm and it is smooth after it settles? Check the turbo inlet pipe foe the pcv connection. Could be cracked and sucks in air after it is warm.

[Birdmandoom]

Originally Posted by weehe126

So no power loss, only happens when warm and it is smooth after it settles? Check the turbo inlet pipe foe the pcv connection. Could be cracked and sucks in air after it is warm.

Correct not a huge power loss but maybe a little. And it settles after 15 seconds or if I press the gas it settles as well. But what I don’t get is if it was sucking in air it would keep sucking it in all the time, not just when I turn it on?

[AlmondJayRoM3]

Originally Posted by Birdmandoom

Correct not a huge power loss but maybe a little. And it settles after 15 seconds or if I press the gas it settles as well. But what I don’t get is if it was sucking in air it would keep sucking it in all the time, not just when I turn it on?

Small vacuum leaks can be masked with some revs and or extra fuel. Cold start high rpm does both so you won’t see during that time. When warm and your idle is too low you might stumble because the ecu can’t compensate for the extra unmeasured air. Then at higher rpms the car is taking in a larger flow of measured air relative to the tiny vacuum leak. If your code reader has the ability to look for fuel trims a vacuum leak would cause them to be way off.

[thejeremyman9]

I suspect it will be very difficult to diagnose a vacuum leak from fuel trims, even if he could access them, which it sounds like it probably can't given hes not tuned and can't datalog. There always some +/- fuel trims and other factors, ethanol fuel % and learned LTFTs among them, will influence STFTs.

Im also fairly certain the DME doesn't use closed loop fueling at all on cold start. I havent logged a cold startup but on every other platform that's how it is. So, that's probably why you dont have the issue when its cold.

You can certainly start with a boost/pressure test and check for a cracked inlet. If you CP is stock that's another obvious thing to check as well.

[Birdmandoom]

Originally Posted by AlmondJayRoM3

Small vacuum leaks can be masked with some revs and or extra fuel. Cold start high rpm does both so you won’t see during that time. When warm and your idle is too low you might stumble because the ecu can’t compensate for the extra unmeasured air. Then at higher rpms the car is taking in a larger flow of measured air relative to the tiny vacuum leak. If your code reader has the ability to look for fuel trims a vacuum leak would cause them to be way off.

Thanks for this info.

[Majmah]

Originally Posted by Birdmandoom

I have a 2013 335 xdrive 166k miles and when the car is warm and I turn it on it shakes and it “gasps for air. During a cold start it doesn’t do it. I get the too lean and too rich code at the same time. I change the maf sensor and that didn’t help: so I have no idea what I could be. Any ideas? Thank you.

Hi, my car the same symptoms! Could you please update on the situation, it would be greatly appreciated!

[n55matthew]

I had an issue like this and it end up being the valve cover, check for airflow around the valve cover to see if it has any air leaks or cracks.

[Majmah]

Originally Posted by n55matthew

I had an issue like this and it end up being the valve cover, check for airflow around the valve cover to see if it has any air leaks or cracks.

Thank you for the insight I’ll have a look!
Best