Originally Posted by
mmigacz
One of your early posts stated that you are planning on doing some modifications to this truck. Currently, is it stock? The reason I ask, is the tune seems to be messed up at highway speeds. The BLM’s are really high (150). It might even be maxed out, where the BLM cant go higher then 150. On a perfect tune they should be around 128 (+/- 5). Your trucks block learn (BLM) is adding fuel adding fuel to compensate for a lean condition. Another strange thing I noticed, was the O2 sensor is swinging around 300 mV. Usually, it swings around 450mv. Yours is swinging to the lean side of stoich. In my opinion your shutter is from a lean fuel mixture. Can you post your bin?