ASPX Wide Band

Hey, if you can swing a 4.9 instead of a 4.2 sensor, they are much better. They use a closed cell reference pump as opposed to a 4.2 open air sample. That means longer life and more accurate readings. A 4.2 behind a leaking exhaust header will throw some crazy readings refferencing off that exhaust leak. The heater integrated into the controller is very important too. The 14.7 has a temperature scale too.