[Sandmansc]

2015 335i

Bmw intake
ER CP
Exhaust: resonator delete/muffler delete

Constant CEL saying too much air in and too much air out.

New one pops up says running LEAN.

it pops and crackles nicely when gearing down. (Usually means RICH right) if it popped and crackles under acceleration it usually means it's Lean.

My shop is a German engineer shop only. They build cars add turbos etc. They say JB4 will fix it because it's not properly tuned.

I've done the same mods to other BMWs and never had a problem.

Burger says JB4 won't fix an engine running Lean.


I've ordered one to see.

Thoughts ?

[ZaneHamdan]

I have same problem pretty much except i get fuel running rich code, not lean. Took it to dealership amd they ended up fixing an injector but still have the same problem. Had an injen i take and threw that on, only became worse then went back to stock. I had a jb4 im there but removed it when i took it in to servicing before this problem happened. Taken it to different autoshops specifying in bmws as well as dealerships and noone has been able to tell me whats wrong. They just have no clue. I already have the jb4 so i might install it today and let you know if it changes anything. Hoping for the best im tired of this problem.

[Sandmansc]

Gotcha. Let me know.


Also. I didn't drive it for 3 weeks from an ankle surgery. (Too much foot in the carburetor

Now my clock will not keep time.
Car starts and runs fine.
I tried a trickle charger as mentioned here in other topics.

[Sandmansc]

So far JB4 has fixed every issue. Wow.

[ZaneHamdan]

So as i was going home to try this out my car actually ended up
Dying on me. Went into limp mode and fuel delivery failure popped up. Still inderwarranty thank god. Sorry i couldnt get any results

[Sandmansc]

Ouch. Well my data shows I was lean at idle but rich under acceleration.

This explains a lot.

The shop scanned my car and said ECN error fuel mix too lean.

But it pops and crackles nicely when I let off the gas and there black crap on the exhaust tips making me think rich.

The JB4 made all of this go away. The car runs super smooth.

Idles better. Better response. And map 5 is super fun. MPG is better.

Pic is going through the Appalachian mountains. Still getting 32ish at 70mph

[Sandmansc]

2015 BMW 335i M-Sport