Renovelo Forum

I’ve had catless headers installed for about a year now with no tune. But I’m finally about to tune my 330i to delete cats and sap. Are there any parameters I can adjust to get the full potential out of the car? Only mods so far are bolt on including the headers, intake, and 2.5” straight pipe. Any guidance would be appreciated

Following. I have a Supercharger install with headers and SAP delete. Would like to get the check engine light out.

I followed along with MS4X Wiki to remove the check engine light as far as removing cats and SAP. Not sure if it’ll be the same seeing as you have the supercharger.
https://www.ms4x.net/index.php?title=Si ... a_Features

I plan to use my supercharger file. It only needs the SAP and O2 delete. The file came with the supercharger from VF Engineering for completely bone stock Supercharger only. I should be able to modify it just like the stock file. If not we'll start from scratch.

I have the SAP and CATs coded out now. I'm looking for help with tuning for the catless headers. The supercharger kit has the tune for everything else. I added the headers after purchasing the kit. Runs great right now, just want to make sure I don't have issues from being too lean or rich. I understand the ECU can adjust, some but I have no idea how much.

Want to repost here just to see if anyone would know what tables I need to adjust, and also possibly how to adjust them. My tuning experience goes as far as finding out how to remove codes and give the car a decent sounding crackle. But as far as adjusting timing and airflow, I have no knowledge

Hi Gildner7215, I followed the same instructions from the ms4x wiki for the sap and o2 delete but i'm still getting check engine codes for the secondary air pump. The hex codes i'm getting are 29B5 and 2760. My emissions monitor is still showing incomplete. Any input on why this isn't working? I'm also on ms45.1. Do you have any input on how to make the SAP show not available in the emissions monitors too?

Turns out SAP is a learned variant based on a power stage diagnosis. Learned variants are set once on a new DME, or when LC_AD_CLR_VAR is set to 1. Learned variants are not changed under any other circumstances. Meaning, unless you know to change LC_AD_CLR_VAR then your car will never know to “relearn” that it doesn’t have a SAP.

I will be testing this in the next couple weeks as weather clears up, but theoretically to disable SAP the only thing you need to do is physically remove it from the car and then change LC_AD_CLR_VAR to 1 and start the car.

This same thing should work for the downstream o2 sensors too btw.

I can confirm that SAP and lower (downstream) O2 sensors can be disabled simply by removing those components and resetting learned variants.

Learned variants are reset by setting LC_AD_CLR_VAR to 1, and then briefly start the car (its possible only turning on the ignition is necessary, but this is the process I used). Turn off the car and change LC_AD_CLR_VAR back to 0. Now your car will begin relearning the learned variants, and if you have SAP and/or downstream O2 sensors removed from the car, you won't get any diagnostic lights as a result.

I figured my problem out a while back. The downstream O2 sensor diagnostics have to remain on.

Because of all the issues I no longer have the custom tune. Got my money back since they couldn't figure it out and I ended up using ByteTuner to fix. Now I need help with header parameters for a supercharged M54. Anybody?

Did you ever figure out parameters for the headers?