While im not an expert nor do I claim alot of knowledge relocating the sensor should help because there is more intake air, as has been said if you had a stock system an you tried it the O2 sensor would foul you up by reporting a rich condition, however with more air then normal an it not getting reported correctly the O2 sensor is still fouling you up by now reporting a lean condition? I dont know if that would hold true for a diesel engine or not but that would be one reason I think relocating the sensor would work.