Morning All! Happy Monday!!
I realize that this might be academic given that we can turn off the codes, but the need to know is winning and I want to see if anyone can explain the causes before I simply turn them off!
I have what is typically the dreaded P0299 code. Underboost! That usually means the turbo waste-gate is dying. I just put in a Frankenturbo F23L, so I am pretty sure that my WG is fine and am turning to tuning. Since I have been driving it with this persistent fault, I have now gained a P0420 (yes, the "your turbo is smoked" joke crossed my mind!) which is a permanent version of the 299.
Since this is a VERY common error on these cars and the standard fix is to replace the turbo and add a tune (typically with the fault turned off), so there is little info to explain what causes the fault and how to properly correct it in the tune.
Does anyone have info on what the ECU is comparing to trip this fault? I cleared it while driving steady state (very low boost) on the freeway last night and it still returned within minutes, so I'm thinking it's at the lower end of my maps, but being relatively new to tuning this way and these ECUs I am not sure.
The car drives good otherwise. I'm still learning the tuning, but it's got no other bad habits except a little knock retard at the high end of the spectrum.
My thoughts on options:
- My WG is not tight enough and needs to be turned up. This isn't easy to adj, so it's not a fav option!
- The lower end of my Boost Duty map needs to be increased.
- Possible boost leak. (Already went here for another issue though!)
- a combo of 1&2?
Anyone got a clue as to what I am missing?
Thanks!
KS