[435MSPORT]

Hi All,

I installed a AFE Magnum cold air intake to my 435i. The transmission seems to jerk a little bit and even created more jerk when operate in Sport mode. Does anyone has experience the same problem? and How do you correct this problem. I've contact AFE regarding this issue. Their response was the car will automatically adjust after the burn-in period. I have great doubt on their response. I am thinking logically, there must be an unbalance ratio of air and fuel in the combustion chamber could lead to this problem. I appreciated your sharing and expertise advice. I do like the exhaust tonality with the AFE intakes.

JB4 stage 2
Mport exhaust
downpipe+catles

[Joe_E]

YES! Finally, someone else has had this issue, although mine is with an injen intake. Have the same issue with the jerk especially in first gear in sport mode.

[BEAR-AvHistory]

FWIW. Some systems are more sensitive than others to changes in the intake tract. In some cases the ECU has enough flexibility to adjust but some never do.

My COYOTE crate motor was tuned by FORD Racing for their intake tract. The motor runs a Spectre CAI in the car. The notes with the engine say that any change in the tract will require a fresh tune. So I took advantage of this for a custom performance dyno tune

The notes with the Spectre indicate the position of the sensor (toward the front of the car) on the tubing with no alternative variation. So even where the pickup is located can be critical for a smooth running car

A later change from the original intake manifold to the BOSS 302 had a note that the car must be retuned after the new manifold was installed.

If the BMW system which has loser tolerances does not stabilize might be a good plan to get a performance tune or replace the CAI with a different one or go back to stock.

Most all CAI's on a modern car don't make extra power but do create a good sound. IMHO the sound is not worth the performance issues that sometime comes with it.

[Sparky2]

I've recently had the same problem after installing an Injen CAI in my 2014 335i. I have JB4, CP, catless DP, and now CAI. Never had the problem before CAI, but I also decided to run a 30% mix of E85 within a day of installing the CAI. So, I wasn't sure if it was the E85 or the CAI that's causing this. Been on for about 1.5 weeks. Going to run 1 more tank of 93 octane through it. If that doesn't fix it, going back with stock intake to see if that helps. Just to note, I had an AFE drop in high flow filter in my stock airbox, no problems.

[mbanks21]

Unplug your MAF sensor. Problem solved.

[eksigned]

Originally Posted by mbanks21

Unplug your MAF sensor. Problem solved.

Wtf. lol

[mbanks21]

Originally Posted by eksigned

Wtf. lol

Why wtf? The maf sensor on aftermarket intakes causes issues with the jb4. Search the boards here its a known issue and resolution. Worked for me and many others

[mike@x-ph.com]

Originally Posted by mbanks21

Unplug your MAF sensor. Problem solved.

Originally Posted by eksigned

Wtf. lol

Mbanks is correct

Unplug the MAF sensor, JB4 will take care of the rest and problem is solved

[Andlee]

I unplug mine and next day engine stall when cold start. Just revert back to stock and everything will be fine.

[STR8-6IX]

put your stock intake back on

[saintpatty]

Originally Posted by mike@x-ph.com

Mbanks is correct

Unplug the MAF sensor, JB4 will take care of the rest and problem is solved

How does JB4 "take care of the rest"?

[saintpatty]

If you have to unplug critical engine components then maybe it's best to revert to normal or look for something that doesn't require such measures.

[mike@x-ph.com]

Originally Posted by saintpatty

How does JB4 "take care of the rest"?

Intake is not causing any harm to the engine, the Jb4 suppress the code.
Same way how it suppresses the downpipe code since it does not cause any harm to the engine either

[mbanks21]

Originally Posted by saintpatty

If you have to unplug critical engine components then maybe it's best to revert to normal or look for something that doesn't require such measures.

Pretty sure the maf sensor is not a critical engine component just as the o2 sensor on a catless DP is not either. Lighten up Francis, you're dealing with aftermarket parts here sometimes you have to do things to make everything jive

[STR8-6IX]

Originally Posted by saintpatty

If you have to unplug critical engine components then maybe it's best to revert to normal or look for something that doesn't require such measures.

Yup!!!! It's not the MAF sensor causing the problem.. that's part of your car! It is the shitty air Intake causing the problems...

[Wires]

Originally Posted by mbanks21

Pretty sure the maf sensor is not a critical engine component just as the o2 sensor on a catless DP is not either. Lighten up Francis, you're dealing with aftermarket parts here sometimes you have to do things to make everything jive

What exactly are you creating the "logic" on? The MAF sensor is required to measure pounds of air into the engine so it can spray pounds of fuel. It's pretty critical.

Unplug it, and the DME will go into a limp mode to deal with the failed input. I'd hardly call that a "solution". Sure it might work "ok", but it's not going to run 100% anymore. Just dump the aftermarket intake.

[jmg]

All this for an air filter that gives you <5hp?

[lens]

Originally Posted by Wires

What exactly are you creating the "logic" on? The MAF sensor is required to measure pounds of air into the engine so it can spray pounds of fuel. It's pretty critical.

Unplug it, and the DME will go into a limp mode to deal with the failed input. I'd hardly call that a "solution". Sure it might work "ok", but it's not going to run 100% anymore. Just dump the aftermarket intake.

It'll only go into limp mode if you don't have JB4 or a flash.

If you do have one or the other, I believe the tune will adjust the air accordingly. My car runs 100% better with the MAF unplugged.

[jmg]

Originally Posted by chaungo

It'll only go into limp mode if you don't have JB4 or a flash.

If you do have one or the other, I believe the tune will adjust the air accordingly. My car runs 100% better with the MAF unplugged.

I'm curious as to how it knows which way to adjust without a sensor to tell it the mixture?

[mbanks21]

Originally Posted by chaungo

It'll only go into limp mode if you don't have JB4 or a flash.

If you do have one or the other, I believe the tune will adjust the air accordingly. My car runs 100% better with the MAF unplugged.

Mine too. I thought the chargepipe was loose but unplugging the maf sensor fixed it

[STR8-6IX]

Originally Posted by jmg

All this for an air filter that gives you <5hp?

Not even... it's all sound no power. You gotta be u plugging shit in your car to get it to work... so stupid.. not worth it at all.

[Wires]

Originally Posted by jmg

I'm curious as to how it knows which way to adjust without a sensor to tell it the mixture?

Exactly. At that point it's using some default canned mapping in the DME mixed with throttle position inputs (aka limp mode using alpha-n type fuel delivery as a backup from the superior speed density mode) to deal with a missing MAF input. It's definitely not 100% better. It just allows the engine to run.