Renovelo Forum

I just recently installed a K&N and some headers and high flow cats, with an EGR delete on my E39 530I. At the moment I'm just messing around with the software trying to understand what everything does. With that being said what does the lambda multiplier, and the lambda additive do. Also what should i do to make my ecu realize that it no longer has an EGR

By EGR, do you mean SAP (secondary air pump)? If so, have a look at the MS4x wiki for tuning advice.

And regarding lambda additive and multiplier, are you referring to the datalog channels? BMW uses a different terminology than the rest of the automotive world for lambda trims. Lambda additive is commonly referred to as LTFT (long-term fuel trims) and lambda multiplier is STFT (short-term fuel trims). For more info, see this document.