[niarmsports]

I straight piped my exhaust and ever since then my mileage TANKED! It was down to 8.3 mpg, had the turbo and tranny "relearned" mileage went up to low 20's then gradually got worse and is back down to 8-9... WHY?

 

[Rustin]

Don't know? Scan it for codes? Did you forget a sensor? have you been driving it normal? And have you changed your intake?

 

[97cummins]

Wow! He straight pipes his truck and the milage drops?
That's a new one on me.

 

[In2Trux]

What Rustin said... Did you eliminate your O2 sensor

 

[Rustin]

:4-dontknow:This one has me baffled? The O2 is the only thing I could think of?:thk:
:sad:​

 

[TPDiesel]

:4-dontknow:This one has me baffled? The O2 is the only thing I could think of?:thk:
:sad:​

Rustin

LB7 LLY and LBZ Duramaxs don't have O2 sensors.

Are you running stock tuning?
Cause most of the times they will throw an EGR Insufficient flow code when you improve exhaust flow. Also might want to clean the MAP sensor.

 

[niarmsports]

I will be running an EFI live tune next week. I'm lost on this too. the last of fuel i ran I only got 200 miles out of. I do have a short drive to work, 2 miles so that is a MAJOR factor but it seemed to do better before

 

[Rustin]

Rustin

LB7 LLY and LBZ Duramaxs don't have O2 sensors.

Are you running stock tuning?
Cause most of the times they will throw an EGR Insufficient flow code when you improve exhaust flow. Also might want to clean the MAP sensor.

:iagree:
WHERE THE HECK HAVE YOU BEEN!
Don't you ever miss another Dmax question again!
:i_rolleyes:​

Did you not notice the smily shaking his head after my O2 post. Really? Common!