Here's a Questions somewhat relative..... I stripped the threads on the bung for my downstream O 2 sensor. I need to weld on a new bung. I was thinkin about grinding down the bung that is there and then welding the new one on top of the old one. If the sensor is out of the "stream of exhaust" a 1/4" or more... would that cause CEL codes to come up? I would think that any exhaust shop should have a bung I could buy and weld on....?