A gas sensor includes a gas sensing element positioned at least partially within a body and exposed at a first end to measure a gas in contact with the first end. The gas sensing element defines an axial direction. A flange extends from the body in a direction transverse to the axial direction. The flange has a first side facing toward the first end and a second side facing toward a remote end of the gas sensor. An O-ring is configured to sealingly position the gas sensor within a bore. An insertion portion of the gas sensor is defined by a wall and configured to hold the O-ring. The wall of the insertion portion is spaced a distance from the body at an axial position of the O-ring to provide a gap therebetween.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 This invention was made with Government support under DE-EE0005975 awarded by the Department of Energy. The Government has certain rights in this invention.