N54 cats and 02 sensors

[fmorelli]

You mean remove the rear o2 influence from the main lambdas? I'm sure I could, however I am unsure if I would/should. They perform a self check on one another, and for most is a good indicator of when SOME o2 sensors are in need of replacement.

The only scenario I would feel comfortable having the rear o2 checks on main lambdas removed would be if the user also had a standalone wideband AFR gauge. Otherwise, you have no clue if the 14.7 AFR you are logging in MHD is a true 14.7AFR.

@jyamona what happens when someone has removed post-cat sensors? I suppose safe code in the DME doesn't compute a correction? Second ... in my case I moved the post-cat 02 sensors to mid-pipe cats ... and there are also ways to mount the 02 sensors with reduced exhaust exposure (so they don't set ... old trick) ... how does that influence the calculation? I guess my thinking ... if one is not running catted DPs one is not running a post-cat 02 scenario as Bosch engineers would have sorted out compute aging on pre-cat sensors.

Do I have this wrong?

Filippo

 

[Jake@MHD]

if one is not running catted DPs one is not running a post-cat 02 scenario as Bosch engineers would have sorted out compute aging on pre-cat sensors.

The ECU is not configured for either of those scenarios.

 

[Rob09msport]

@jayoma Wouldnt accurate voltage clamping without clipping signal or altering frequency aka my 22 percent reduction which mimics a healthy o2 sensor work properly. It is essentially giving signal same as if their were cats. I know a dsp would be even better but 5 dollars builds 2 voltage clamps that's why the 2.2k runs inline then after the 2.2k a 10k runs to signal ground. I achieved obd readiness on my second drive, this with no cats whatsoever with catted dp selected in flash time options. Other sims or foulers never worked in past cause I have an 09 which i hear is finicky and i couldn't source a n54 fix sim with adjustable pot.