"cleaning exhaust" speed up or slow down
 

so go the "cleaning exhaust" message while I was on the parkway....which made me wonder....since this system works off the exhaust back pressure sensor...should I speed up or slow down. some random thoughts

a.) if I speed up , more ambient air flows across the cooling system
b.) if I speed up , the engine generates more heat
c.) increase in engine rpm could increase the readings of the exhaust back pressure sensor
d.) if I slow down, engine produces less heat
e.) if I slow down, less ambient air flow to cool off engine
f.) if I slow down, less pressure in the exhause for the exhaust back pressure sensor to detect.
g.) going faster and running up the rpms while in "cleaning exhaust mode" will increase the effects of the exhaust flame out #7 and 8 are doing to burn off soot.....but that will also tax metal surfaces of turbo, number 1, 2, 3 temp sensors, exhust back pressure sensor, etc.

so whats best and why?

Get on the freeway and drive...




Here is the deal, the filter pressure sensor and ebp sensor take info from maf and map as well. Speeding up increases fuel flow and boost, this means more heat in the dpf. It will speed the process up a little. And its a common misconception that there is "fire" out of cylinders 7 and 8... If you wants the egt sensors you will notice that around the dpf is where the heat gets trapped. The idea is not to increase heat in the motor, it is to get the fuel in as close to an atomized state as possible into the dpf. The dpf is what gets over 1k* and this is where soot gets burned off.






Here is what you as an owner need to know... When you see that message try and be on the freeway and let it finish. Having the motor under load while going through regen is the most efficient way of getting the job done. This also gives you a chance to let things cool as you get off the freeway and drive home.


You really don't need to over think the process... It is very simple and isn't an issue provided you let it finish. I always made a habit of down shifting and building boost to try and push any ash or what have you out of the dpf after regen, but this really isn't necessary.

Thanks for this. I wondered the same thing.