Check For Busted O2 Sensor?

[bj_dove]

Is there any easy way of checking if my o2 sensor is stuffed?

My economy has gone out the window lately, 3/4 tank of ultimate 98 gone after 150km and im babying it everywhere, can even smell its running rich.

Any ideas of an o2 sensor test?

Cheers, Bart.

[Pauly33GTS-t]

list mods.

[bj_dove]

Completely stock apart from;

Pod filter (no CAI)

Stainless split dump, high flow cat, fujistubo cat-back

So stock ecu, stock boost running straight off actuator, very stock!

[Pauly33GTS-t]

ehe, yes you do have a problem with economy...

If it is hunting at idle (always fluctuating revs) then im sure its your O2 sensor, if I were you though id be more confident with a second opinion from another person on the forums here...

[bj_dove]

yeah cheers, when cold (anywhere under operating temp) it does hunt at idle. Think ive got an o2 sensor off my old 32 here might give it a try, cheers

[MANWHORE]

won't work.

best way to check - run it on a consult diagnostic screen. best investment ever. if you don't wanna spend that much money, at least buy a consult cable.

[Pauly33GTS-t]

manwhore wats the max latency that the injector cycle should be on consult, I have a greddy intelligent informeter and Im trying ot configure it to show percentage injector duty cycle and then set warning points. i love this thing... lol.

[blind_elk]

yeah cheers, when cold (anywhere under operating temp) it does hunt at idle. Think ive got an o2 sensor off my old 32 here might give it a try, cheers

"Hunting" is generally a sign of a gummed up AAC valve. And the O2 sensor is unlikely to be used at idle, or when the engine is not up to operating temp. So, if you only do short trips that don't get the engine up to temp properly, then you are going to chew petrol.

How to test - check the voltage coming off the middle wire of the sensor - it should be oscillating around 0.5V (say 0.3 - 0.7). If it is constantly high (1V) or low 0V) then there is a chance your O2 sensor is cactus.

You might also want to check that the sensor is getting 12V on one of the other 2 wires.

[bj_dove]

cheers elk, ill get onto it tomorrow.

was gonna try and get diagnostic codes from the ecu, but its an odd 'genuine nissan remanufactured' ecu. wonder what thats all about....?

[InterCooL]

multimeter is the way to check. takes 2 mins.

measure it at idle, give it a rev, and hold it at a sustained rpm, say 2500rpm.

see if you have fluctuating volts

last skyline i checked (a friends) it was dead as a doornail, got no change in volts. replaced it and the car got an extra 50-80km's iirc (hopefully you gain some more!)

also on my skyline i changed spark plugs, cleaned afm and got new coilpacks, that gave me 2L / 100km better economy! my plugs were old though