Thread: D2 Blowing Smoke

Gday all - My D2 is getting very poor fuel economy and has starting blowing smoke - it is most noticeable under acceleration while towing but can be seen at idle also. Any ideas?

Redslayer, it sounds as though your car is running too rich. There will be fault codes related to the fuel system malfunctioning. Usually, they are as follows:

Engine running too lean:

Fault 26 P0171 Fueling adaption ti Multiplicative Maximum value Exceeded
This fault code means that the fuel system is too lean on bank 1.

Fault 34 P0174 Fueling adaption ti Multiplicative Bank 2 Maximum value Exceeded
This fault code means that the fuel system is too lean on bank 2.

Engine running too rich:

Fault P0172 Fueling adaption Additive Bank 1 Minimum value Not Reached
This fault code means that the fuel system is too rich on bank 1.

Fault P0175 Fueling adaption Additive Bank 2 Minimum value Not Reached
This fault code means that the fuel system is too rich on bank 2.


These are the 02 sensor faults we had occurring, which indicated that the 02 sensor was failing:

Fault 10 P0130: 02 probe probe Pre-Catalyst value not plausible.

Fault 18 P0130: 02 probe probe Pre-Catalyst value not plausible.

However, the 02 sensor was not the fault. The trouble was the MAF sensor.

Our 1999 Discovery II V8 ran lean with the 02 sensor faults, and occasionally with the running-too-rich codes. It also ran rough when cold, but accelerating the engine caused the roughness to disappear.

During this lean time, we could get 1000k’s on a single tank. After replacing the MAF sensor, we only get 500k’s at the most on a single tank.

However, when we replaced the MAF sensor all of these faults, including the 02 sensor faults and the running rough disappeared!

LRT