gmctd wrote:
papaindigo wrote:
Just to rain on the debate a bit per my previous post "the factory MAP senor on my 05 and my son's 06 are both the Bosch 0 281 002 437 which can be found online for about $70-$90 based on the Bosch PN" and MrMopar64 originally said that DCJ used the 845 on "newer" engines but did not specify what that meant. Could be the 07 and later VM 2.8 but I'm just guessing.
Regardless if PN68031593aa is the most recent DCJ PN for the 05/06 KJ CRD then that part appears to be the 845 and idParts has them for ca. $25.
In any case even if the "electronic" debate, which I don't pretend to understand, is valid (I presume it is) and there is some upper end boost limit (could be) as a practical matter those owners using the 845 have not reported any issues.
845 would have increased upper limit in the '05s, maybe matching the '06s
Could be important that some have reported fuel mileage increase after replacement - if proven, that would be reason enuff to rush rite out and replace the 437, no matter what condition it is\was in - even if the original was crudded up, as noone reported substantial gains after cleaning\reinserting
I may have uncovered a problem with using the 845 sensor.
For the last couple months I have been using a Yeti Stage 2(free) tune and the Bosch 845 MAP sensor. Power and boost have been great but have noticed a significant drop in MPG and heavy amounts of black smoke when accelerating from a dead stop.
It was the heavy black smoke that concerned me.
It didn't take much to create that smoke either, just light to moderate acceleration from a dead stop or just rolling at 5 mph.
The only way to keep the black smoke from happening was to just ever so lightly press on the accelerator pedal.
Boost pressure, as read using TorquePro, would max out at 22.3 psi under moderate acceleration at any speed.
Once moving at a good rate, I could accelerate with no heavy black smoke.
I checked the turbo actuator and vacuum lines and solenoids and all are functioning normally.
Boost hoses and intercooler are tight with no leaks.
It just seemed that the ECU was dumping too much fuel without adequate boost and therefore producing a heavy thick cloud of black smoke.
So I switched back to the OEM 437 MAP sensor and the black smoke has been significantly reduced. Max boost, as read using TorquePro, is now 21.3 psi and I have to push the accelerator pedal a little bit harder to get it there.
It seems that, with this tune at least, the difference in the two sensor calibrations is enough to fool the ECU into thinking that the turbo is producing more boost than it actually is.
Stock tunes may not have any noticeable effect.
Or maybe this was just a fluke and the 845 sensor I was using had some weird problem.
All I know is that the difference is significant.
I dont know if this MAP sensor change will effect my MPGs. I have worked through multiple engine issues lately so only time will tell.