[F90bmwmastertech]

Originally Posted by AngryInch

Hmm I don’t get why some are thinking removing a critical engine part would not affect warranty? You’re increasing the power of the engine, changing the fueling and tune of the car by removing the downpipes as the dme tries to auto tune to compensate for the increased flow. More power, more air and fuel.

It’s not like you simply changed the muffler… what do you have against the jb4?

Not trying to rain on your parade, I just don’t see the logic?

I work for BMW as a master tech…been 16 years meow. Having a catalyst efficiency fault is not comparable to having your car flagged in our system for suspicion of engine tuning, which even a JB4 can do as the DME can data log. The DME constantly has to adapt to the various weather, altitude, etc conditions and reducing back flow is a bit different than intentionally altering the programming of the DME or fooling them i.e, JB4 to read numbers that are out of nominal range.

[Kponti]

Originally Posted by F90bmwmastertech

I work for BMW as a master tech…been 16 years meow. Having a catalyst efficiency fault is not comparable to having your car flagged in our system for suspicion of engine tuning, which even a JB4 can do as the DME can data log. The DME constantly has to adapt to the various weather, altitude, etc conditions and reducing back flow is a bit different than intentionally altering the programming of the DME or fooling them i.e, JB4 to read numbers that are out of nominal range.

This cat's serious!

[brad65ford]

Originally Posted by F90bmwmastertech

I work for BMW as a master tech…been 16 years meow. Having a catalyst efficiency fault is not comparable to having your car flagged in our system for suspicion of engine tuning, which even a JB4 can do as the DME can data log. The DME constantly has to adapt to the various weather, altitude, etc conditions and reducing back flow is a bit different than intentionally altering the programming of the DME or fooling them i.e, JB4 to read numbers that are out of nominal range.

Can you share with us what you'd suggest for more power? Not sure if bolt ons are work it on this car what what your sharing.

[AngryInch]

Originally Posted by F90bmwmastertech

I work for BMW as a master tech…been 16 years meow. Having a catalyst efficiency fault is not comparable to having your car flagged in our system for suspicion of engine tuning, which even a JB4 can do as the DME can data log. The DME constantly has to adapt to the various weather, altitude, etc conditions and reducing back flow is a bit different than intentionally altering the programming of the DME or fooling them i.e, JB4 to read numbers that are out of nominal range.

I see what you’re saying… I thought they would also flag a car with the cats removed and down pipes added, is this not the case?

[F90bmwmastertech]

Originally Posted by AngryInch

I see what you’re saying… I thought they would also flag a car with the cats removed and down pipes added, is this not the case?

Nope. The flagging is not necessarily done by a technician or foreman. It’s whenever we connect the car and scan it for diagnosis the data that’s sent behind the scenes to BMW. Information that we as techs and foreman don’t even have access to like any data logging or over rev info and that’s when a hard fault is stored for suspicion of engine tuning.

[AngryInch]

Will you tune when the warranty has expired?