Checking O2 Sensor - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Pacman · 06-14-2005, 01:10 AM

Ok, I don't know if its my fuel gauge, my sending unit, or if its actually the O2 sensor acting up again. Can someone tell me how to check it, or where to look in the FSM cause I'm not seeing how to test it. I notice that the gauge fluctuates on different hill inclines/declines. I also notice that it seems like the first half of the tank drops fast and the second half (or quarter tank cause I fill up at 1/4 tank) gets used up slower (but still fast). There is no visual leaks around the injectors, lines, or tank. The engine is in good condition, newer NGK plugs, year old wires, dist. cap, and rotor, 6 month old O2 job by professional (I screwed in up by cutting the OEM connector; O2 wired right up on harness), 6 month old Cat. Anyone have anything similar happening?

EDIT: The exhaust isn't grounded, can that cause anything bad (like O2 sensor malfunction, cat not working right, higher emssions)?

06-14-2005, 01:10 AM	#1
Pacman Zilvia FREAK! Join Date: Sep 2003 Location: Ohio Age: 37 Posts: 1,149 Trader Rating: (1) Feedback Score: 1 reviews	Checking O2 Sensor Ok, I don't know if its my fuel gauge, my sending unit, or if its actually the O2 sensor acting up again. Can someone tell me how to check it, or where to look in the FSM cause I'm not seeing how to test it. I notice that the gauge fluctuates on different hill inclines/declines. I also notice that it seems like the first half of the tank drops fast and the second half (or quarter tank cause I fill up at 1/4 tank) gets used up slower (but still fast). There is no visual leaks around the injectors, lines, or tank. The engine is in good condition, newer NGK plugs, year old wires, dist. cap, and rotor, 6 month old O2 job by professional (I screwed in up by cutting the OEM connector; O2 wired right up on harness), 6 month old Cat. Anyone have anything similar happening? EDIT: The exhaust isn't grounded, can that cause anything bad (like O2 sensor malfunction, cat not working right, higher emssions)?