[M1LL10NG30]

Hey everyone! I'm someone who is new to the forums, BMW, and tuning. Wanting to get some help hopefully! I've had 4 G30s since 2020 and each one has been amazing, 3 540's and a M550i. I now have a 2017 540i because my GS350 was totaled and I needed a car ASAP! There is my background.

So I have the Fi exhaust (muffler & midpipe) ordered but I'm hung up on either a catless DP or catted. Does a catless/catted DP require a tune from a reliability stance? I'm worried that if I install one or the other without a tune, that it won't run correctly. Not worried about emissions, smell, or CEL.

If a tune is needed, what is a good pick? After reading some threads the past few months I kept seeing that one tune (cannot remember the name) gave some users a drivetrain error to where they would have to shut off the vehicle and turn it back on or re-install it? Apologies if I got that completely wrong. Are there any other major benefits of a tune other than power increase? I'm mainly looking to increase the sound and responsiveness as I am not trying to gain any power. Not opposed but it isn't my main focus.

Purchased the vehicle with 60k miles on it and I just crossed 80k. 1st owner followed BMW service intervals. I've done oil changes every 5k using OEM, set of OEM spark plugs done at 70k, and next service will be trans flush. My drive is 60 miles roundtrip, 5 days a week. Will be needing a new flex disc soon sadly as mine is starting to crack a little bit.

I greatly apperciate any and all responses, I'm sure I'll get flamed for opening a new thread but I have no clue how these forum sites work lol.

Thank you anyone who reads or replies!

[buddyboy]

Originally Posted by M1LL10NG30

Hey everyone! I'm someone who is new to the forums, BMW, and tuning. Wanting to get some help hopefully! I've had 4 G30s since 2020 and each one has been amazing, 3 540's and a M550i. I now have a 2017 540i because my GS350 was totaled and I needed a car ASAP! There is my background.

So I have the Fi exhaust (muffler & midpipe) ordered but I'm hung up on either a catless DP or catted. Does a catless/catted DP require a tune from a reliability stance? I'm worried that if I install one or the other without a tune, that it won't run correctly. Not worried about emissions, smell, or CEL.

If a tune is needed, what is a good pick? After reading some threads the past few months I kept seeing that one tune (cannot remember the name) gave some users a drivetrain error to where they would have to shut off the vehicle and turn it back on or re-install it? Apologies if I got that completely wrong. Are there any other major benefits of a tune other than power increase? I'm mainly looking to increase the sound and responsiveness as I am not trying to gain any power. Not opposed but it isn't my main focus.

Purchased the vehicle with 60k miles on it and I just crossed 80k. 1st owner followed BMW service intervals. I've done oil changes every 5k using OEM, set of OEM spark plugs done at 70k, and next service will be trans flush. My drive is 60 miles roundtrip, 5 days a week. Will be needing a new flex disc soon sadly as mine is starting to crack a little bit.

I greatly apperciate any and all responses, I'm sure I'll get flamed for opening a new thread but I have no clue how these forum sites work lol.

Thank you anyone who reads or replies!

It will throw a CEL without a tune and might not run great so a tune is the correct way to go, MHD or BM3 are great options you can install yourself and perfectly adequate for a stage 2 tune, just pick the map to suit the fuel type you want to run

[Doctor X]

Originally Posted by M1LL10NG30

Hey everyone! I'm someone who is new to the forums, BMW, and tuning. Wanting to get some help hopefully! I've had 4 G30s since 2020 and each one has been amazing, 3 540's and a M550i. I now have a 2017 540i because my GS350 was totaled and I needed a car ASAP! There is my background.

So I have the Fi exhaust (muffler & midpipe) ordered but I'm hung up on either a catless DP or catted. Does a catless/catted DP require a tune from a reliability stance? I'm worried that if I install one or the other without a tune, that it won't run correctly. Not worried about emissions, smell, or CEL.

If a tune is needed, what is a good pick? After reading some threads the past few months I kept seeing that one tune (cannot remember the name) gave some users a drivetrain error to where they would have to shut off the vehicle and turn it back on or re-install it? Apologies if I got that completely wrong. Are there any other major benefits of a tune other than power increase? I'm mainly looking to increase the sound and responsiveness as I am not trying to gain any power. Not opposed but it isn't my main focus.

Purchased the vehicle with 60k miles on it and I just crossed 80k. 1st owner followed BMW service intervals. I've done oil changes every 5k using OEM, set of OEM spark plugs done at 70k, and next service will be trans flush. My drive is 60 miles roundtrip, 5 days a week. Will be needing a new flex disc soon sadly as mine is starting to crack a little bit.

I greatly apperciate any and all responses, I'm sure I'll get flamed for opening a new thread but I have no clue how these forum sites work lol.

Thank you anyone who reads or replies!

Highly recommend getting some downpipes.

If you aren't interested in power output you can easily go with some catted ones. In that case you won't need a tune.

Now if you want to wake the car up and increase it's responsiveness without worrying about too much of a power jump.

I'd go with catless VRSF 4.5" downpipes, then get a bootmod3 tune and just rune the Stage 1 tune.

Honestly the stage 1 in my opinion is how the car should've came from factory.

Stage 1 is very conservative.

[540iSUP]

The drivetrain error is from the BM3 tune. I had that issue and BM3 fixed it the next day after I emailed them. They are very responsive.

If you only really want the sound, just stick with the exhaust and go from there. If you want more sound, a High Flow Cat will achieve that, but without a tune. If you still think its not loud enough, go for a catless DP. If you're not looking for power, you can purchase a tune and leave it OEM and disable the cat sensor via the tune. At that point you might as well just download stage 1 because you're essentially paying for it anyways.

You will not need to go to stage 2. Stage 1 has the biggest torque and HP delta from OEM compared to stage 1 to stage 2 anyways.

Once you get used to the power, you might get the itch to go stage 2.

You can run the car with a catless DP and no tune, but you will get a CEL. It will not affect drivability, but it also won't be able to take advantage of the free flowing exhaust.

No question is bad question, so get that out of your head. We are all here to help you achieve your goals and answer any questions that we can. There are a lot of very knowledgeable people here so ask away!