Make sure you use good grounds, if not you will get false readings!!! engine preferably. Run all the grounds(my xd-16 has 3 = 1 for system ground, 1 heater ground, and gauge.)thru the firewall and solder them to one lug and attach that lug to the engine/head/tranny. Hook power to a switched 12v supply. You probably need to do a free air calibration on the sensor before you screw it into the exhaust also. Good Luck