System too lean bank 1 and 2

[BMWCal_2000]

Hi guys
This is for the E85 SE 3.0L 2004
I’ve recently upgraded my stock air filter to a Cold air intake Cone filter (PRORAM 90mm Neck large cone air filter with velocity stack and coupling)
For the first 2 days I had no issues and it sounds really nice.
But unfortunately today I had a Engine Warning light appear on my dash. I plugged in my diagnostic tool and it flagged up saying;
P0171
System too lean bank 1,
P0174
System too lean bank 2.
I was hoping someone may understand why this has happened and if anyone may have any solutions that I can try to hopefully resolve this.

 

[colb]

Most likely to be a split or hole in one of the intake rubber hoses, since you have been messing about putting the new air filter in I would hazard a guess it might be the intake hose with the offshoot to the idle control valve that has split. The unmetered air getting in after the Maf will screw up the fueling when the exhaust sensors see the extra air in the exhaust, it will think it is running lean and command more fuel at the injectors to get it running richer. It will do this until it gets to adding 20% more fuel then realise its not rectifying and set the EML on the dash and set fault codes.
Here is a youtube video, not on a Z4 but same principle
https://www.youtube.com/watch?v=10kcAY0LJ4M

 

[Ewazix]

I don't understand how it can be a "cold air intake"? It seems to be drawing air from directly above and behind the radiator, surely the worst place to stick your intake? :?

 

[PerryGunn]

I don't understand how it can be a "cold air intake"? It seems to be drawing air from directly above and behind the radiator, surely the worst place to stick your intake? :?

+1 The standard setup takes air from behind the grill/in front of the radiator so will be taking colder air

I think filters like this are more for 'Max Power' bling than anything else

 

[Rockhopper]

All they do is make more noise. Standard with a clean filter is almost always better in terms of performance and so on.

 

[BMWCal_2000]

Thank you to everyone for the advice but I have decided to go back to the original filter for a few reasons, the main reason being that the car was not preforming as well as it used to and would not adjust the fuel to air ratio which lead to the car having a continuous engine warning lights appear on my dash no matter how many times I would clear it, it would not correct itself. also I couldn’t hear a massive difference in the noice the engine was making and the main reason I decided to swap my filter was for a cheaper option to get more sound out of the car. Not 100% certain if I tried every option to fix these issues but I’m not patient enough to keep playing around with it. I recommend sticking with the original paper filters.

My next change will be on the exhaust because my back box is hanging off and held on with cable ties lol, so I think I would like to go for a back box delete and maybe have a quad exhaust tip fitted rather than the standard dual exhaust tip let me know what your opinions are on this topic

 

[enuff_zed]

Good move with the intake.
I think the majority consensus is that deleting the back box will lead to droning and an extremely chavvy sound.
If you do a few searches on here you'll find lots of references to a method of opening the back box and modifying it to give a nicer note, lots of pops on the over run, but not completely antisocial.