hear ya go hear is what the exaust bung looks like





the sensor screws into it and that the holds the sensor in the flow of exaust gases if it was flaping around in the exaust you will get a siiiiiite reading. ive found the exaust bung is shit with "big" tail pipes it will only give a good reading when the gases are flowing quick ie WOT ect ect i think air tends to waft into the tain pipe giving falce reading's i would defantly weld the bung into the down pipe (about 2 feet from the turbo) and see what happens then