was jacking up to maxipad to test my o2 sensor to see if my leaking injector had killed it... I look at the connector and the ecu side connector red wire was broke off... for now I think im going to cut both connectors off and use wire connectors and hot glue to seal water out.

Im just curious as why the car when warm seems to run fun, accelerate fine and all that, if that wire has been disconnected? my gas mileage could be better, hopefully that broken wire was the reason for that.

Im wondering if its ok to just get rid of the o2 sensor connector and just have the wires stripped and connected permantly? Or should I just do this as a temp fix and go get a connector from a junk yard? what do you guys think?

 

you're exactly right about the middle paragraph. The car will not read 02 until warm regardless, and once warm, a disconnected 02 will make it run rich (ECU failsafe mapping). Rich means bad gas mileage.

what i'd do if i were you is take a small flat-head eyeglasses screwdriver and pop just the one connector out of the plug on your car, as well as the same wire at the JY... then just snip that wire and put it in your pocket and wander out. or pay for it but it's a single 6inch wire... maybe 50 cents? w/e. anyhow search for the 9007 conversion thread for instructions on how to pop wires out of harnesses. that way you can pop the broken wire out of yours, then slip the good unbroken wire in its place, splice just that one wire (rather than all 3), shrinkwrap, done.


if you go the hardwire route make sure to be careful when wiring. my sensor has the same colors, in different positions as some wires on my car-side harness. black goes to white, and red to black, on mine. and white to green i think? something stupid like that.

 

luckily my wires are all same color, white-white, red-red, black-black. ya electrical connectors are real cheap at this pull a part I know. I need to get a new tps connector and some vtc connectors too. Thanks for the tip on just opening the connector and doing it that way. Im going to hardwire it for now until I can score some connectors at a junk yard, they usually only have 1 or 2 maxima's when I go look =(

question...on the white wire, theres a wire wrapped around that with black wrapped around that on the ecu side...like its a shield for the wire or something i dont know. why is it like that?

 

eh? haven't seen that one. problem is if you hardwire them then it'll defeat the purpose of picking pins out of the plug. if you really need to just get a pair of 3m splices, a male/female quick disconnect, and tap each side of your red wire and connect the m/f thing together. voila. that way it's removable for the future without cutting wires, and you can use hot glue on the end where the wire goes into the quick disconnect, and i think the junction of the m/f is pretty watertight. so if you ever get a new 02 sensor you can just tap the red wire with another splice and cut your tap wire off your old sensor (cutting it right out of the splice) and putting it into the new splice. you can do that over the course of several sensors before the wire is soo short to use anymore, as if you'll REALLY need more than 2 sensors in the car's lifetime.

 

Generally O2 signal level is ridiculously low for vehicle use, jumping only between 0 to 1V. Also the cabling is longer than it should, connectors do add to this poor design Such signals are easily distorted via outside interference, and need shield. This shield has to be grounded from computer side; oftentimes Nissan groundings are a mess; confuzean logic, no gnd-rules observed.

The signal is better when wires are soldered, don't bother adding oxidizing connectors... Generally the thicker the signal wiring, the better reception.

 

how can i test if the o2 sensor itself is still in good working order? I mean I had a leaking injector and if this wire has been disconnected for a while, its been running richer than it should and could of maybe damaged the o2 sensor?

 

Its rather robust animal, should be ok.

Above idle, say 1200-1500rpm, the signal fluctuates between 0 and 1 Volts. The higher the rpm, the more the signal fluctuation speed. I have made a led pillar into cabin, you may also purchase some ugly O2 indicators for 40$.

...but u wont get this one from shop, located at mid console, see http://www.cardomain.com/ride/748507/9


Its good to know whats happening, you can hear the ECU/engine tune, observe from indicator leds (multimeter?) how injection is tuned accordingly (hi/low/hi/low...) by ECU adjusting, say at at 1500 rpm.

The sensor is tuned to certain oxygen content mixture... START: When mixture (oxygen content) goes up, O2 sensor signal jumps to one volt. Then ECU decreases injection -and- mixture goes down. Then O2 sensor detects this change, its signal drops to zero ... and now ECU increases injection --->GO TO START

ECU has a special program meant just to test the O2. ECU self diags, See http://www.cardomain.com/ride/748507/21

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I just took couple of video clips ... not too god but shows wassup Ou too. Maybe I could sell these 30$ shipped...?
http://s305.photobucket.com/albums/n...arP4301988.flv
http://s305.photobucket.com/albums/n...arP4301994.flv