[manni22gp]

Hey everyone.

I'm getting a new M240i xDrive and will be doing some mods - MSS suspension, 21" custom wheels, some M Performance aero goods, and finish off with catless downpipe and tune.

With regards the catless dowpipe and tune - I don't want to pursue the femto option and feel more comfortable with possibly the JB4.

I'm clueless on whether there is custom options on the JB4 with regards going the catless downpipe route - will the JB4 disable the "check engine light"? That would be a major requirement for me - if it can't, I'll skip any kind of engine mods and stick to cosmetic.

Lastly, assuming the JB4 and catless downpipe are a possibility, and taking into account I'll not change rest of the exhaust system, and fuel availability is 98 octane, what kind of HP increase would I be looking at?

Thanks all in advance.

[mike@x-ph.com]

No custom map; the map is significantly dependant on your fueling, not your downpipe.

Unfortunately with the Jb4, the downpipe will trigger the check engine light.

[oldbmwtech]

Originally Posted by manni22gp

Hey everyone.

I'm getting a new M240i xDrive and will be doing some mods - MSS suspension, 21" custom wheels, some M Performance aero goods, and finish off with catless downpipe and tune.

With regards the catless dowpipe and tune - I don't want to pursue the femto option and feel more comfortable with possibly the JB4.

I'm clueless on whether there is custom options on the JB4 with regards going the catless downpipe route - will the JB4 disable the "check engine light"? That would be a major requirement for me - if it can't, I'll skip any kind of engine mods and stick to cosmetic.

Lastly, assuming the JB4 and catless downpipe are a possibility, and taking into account I'll not change rest of the exhaust system, and fuel availability is 98 octane, what kind of HP increase would I be looking at?

Thanks all in advance.

Get an 02 sensor defouler. Thou illegal no CEL.

[BG42]

unless they are emissions testing in abu dhabi the check engine light wont really affect much just kinda annoying. The JB4 will most likely void any engine warranty anyway if they figure out its caused by it. That kind of stuff you either do it and are ok with the consequences or you just stick to cosmetic mods maybe an AA downpipe. IF you are after more hp just buy an m2 has warranty and more power from the rip.

[Rdurty2]

Just an FYI that having the CEL from a catless down pipe will prevent you from using remote start, if that is something that matters to you.

[manni22gp]

Originally Posted by mike@x-ph.com

No custom map; the map is significantly dependant on your fueling, not your downpipe.

Unfortunately with the Jb4, the downpipe will trigger the check engine light.

Cool - thank you for clarifying.
Realistically, what would be the difference in performance between full decat, and high-flow cats?

[manni22gp]

Originally Posted by oldbmwtech

Get an 02 sensor defouler. Thou illegal no CEL.

That's a option - would you able to guide me to a source to get?

[manni22gp]

Originally Posted by BG42

unless they are emissions testing in abu dhabi the check engine light wont really affect much just kinda annoying. The JB4 will most likely void any engine warranty anyway if they figure out its caused by it. That kind of stuff you either do it and are ok with the consequences or you just stick to cosmetic mods maybe an AA downpipe. IF you are after more hp just buy an m2 has warranty and more power from the rip.

Seeing the CEL on will definitely drive me nuts.
M2 is too much - I'm getting the car for my wife.

[oldbmwtech]

Originally Posted by manni22gp

That's a option - would you able to guide me to a source to get?

Just Google 02 sensor defouler, I believe it's the same as a spark plug defogger.

[Rdurty2]

I don’t understand wanting to do all of these mods before you even get the car.

Stock power is more than sufficient for most people. You could probably count on 1 hand the number of people here able to push this car to its limits.

Drive the car stock for a while and you may find you don’t need any of this stuff.

Power difference between a catted down pipe that will not throw a CEL vs catless is single digit HP. Barely noticeable. The GESI cats that are guaranteed no CEL are really good, and good for up to 800hp or something.

[mike@x-ph.com]

Originally Posted by manni22gp

Cool - thank you for clarifying.
Realistically, what would be the difference in performance between full decat, and high-flow cats?

no difference on stock turbo

[manni22gp]

Originally Posted by oldbmwtech

Just Google 02 sensor defouler, I believe it's the same as a spark plug defogger.

Thank you.

[manni22gp]

Originally Posted by Rdurty2

I don’t understand wanting to do all of these mods before you even get the car.

Stock power is more than sufficient for most people. You could probably count on 1 hand the number of people here able to push this car to its limits.

Drive the car stock for a while and you may find you don’t need any of this stuff.

Power difference between a catted down pipe that will not throw a CEL vs catless is single digit HP. Barely noticeable. The GESI cats that are guaranteed no CEL are really good, and good for up to 800hp or something.

"I don't understand..." - of course, it's not you, it's me.

There are those that like stock cars, and there are those that like to mod. I'm not doing wild stuff by any stretch of the imagination.

Headers and a tune would be the low-hanging fruit - easy enough to access, and worthwhile. Bonus points for the much improved sound.

Her current car, an X4 28i, has Dinan Stage 1 and AC Schnitzer exhaust, plus M Performance accessories.

I have an E39 530i that I spent huge time and effort cleaning up - no engine mods at all as it's not the point for that car - but visually I lowered it, installed 18" M Parallels, and finished off with Alpina front and rear spoilers.

I also have a Cayman GT4 - stock aesthetics, but catless headers and tune.

So yeah, M240i will get mods - stay tuned for the final outcome.

[Rdurty2]

Originally Posted by oldbmwtech

Just Google 02 sensor defouler, I believe it's the same as a spark plug defogger.

Most won’t work long term. Maybe for a couple hundred miles but the cel usually comes back.

Some people luck out for longer and others don’t. I’ve noticed what may work good on one persons car doesn’t necessarily work as good on someone else’s. It’s a crapshoot.

[BG42]

Better off just slapping some electrical tape over the CEL like the old days. Like you said its just your wife driving it anyway would she care?

[manni22gp]

Originally Posted by BG42

Better off just slapping some electrical tape over the CEL like the old days. Like you said its just your wife driving it anyway would she care?

I do care - attention to detail - my OCD would kill me.