"check engine" - oxygen sensor code...

[bluedraco]

hey guys

i was driving along today when my check engine light came on...it stayed on and is still on now every time i drive the car (never goes off unless i turn the whole car off)...

i used a multimeter and checked for what code it was...it went up to 12v and stayed there for a second and then went to zero, and then quickly read 12v, and then back to zero...it then repeated this over and over again so i'm assuming that is the code (long, short)...from what i have gathered this is 10 + 1 = 11 meaning oxygen sensor...

i actually replaced my oxygen sensor only a few weeks ago with another 4 wire one...i tripple checked the connections and i'm sure it's fine but only today the check engine light came on and it seems like something isn't right...

the old oxygen sensor had 4 wires...2 black, 1 white and 1 blue...2 are obviously for the heater and 2 are for the oxygen sensor readings (sensor + ground)...the new oxygen sensor had the same coloured wirings and stated in the instructions that blue is for the sensor signal wire, white is for the sensor ground and the two black are for the heater (which it claims is non-polarity dependent)...

i'm trying to figure this one out...either the sensor is a dud (i doubt it, already had the first one i put in replaced because it wasn't working right, and they replaced it after i had a MASSIVE argument with them about it) or something with the wiring is wrong...

this really sucks...i'm not 100% sure i read the codes right but i looked and looked and looked and looked and looked and it just repeated the one long, one short pulse which is code 11, oxygen sensor...

i'm stuck as to what to do...i have NO idea where to go from here...i mean, i could always put my old oxygen sensor back in as i know that works but it is 230,000km old and is certainly not as good as a new one...

any advice/tips/suggestions/help of any kind?

i'm really very confused as this is very frustrating and i really don't have the option of getting a refund AT ALL...i've already taken one back because it didn't work and if i try it again, they'll send it away for testing and more than likely it will probably work (knowing my luck) for them and they'll just send it back to me...

this sucks

EDIT - i think on monday (when my mechanic is open and i can borrow his oxygen sensor removal tool) i'll just put my old sensor back in (the one that works but is 230,000km old) and drive around a bit and see if the light eventually goes out...if it does, i know for sure it is my new oxygen sensor and i can worry about it then...if it doesn't fix it then either i need to reset the ecu (do i?) and drive around a bit more or it isn't my oxygen sensor...*sigh*...even more stuffing around!

[bluedraco]

guys, i'm going to be redoing my wiring for the oxygen sensor tomorrow...i want to try it out before i try to get a replacement as i want to see if the connector is the problem...

i'm going to cut the connector out of the equation completely and just solder the oxygen sensor wires to the wiring before the connector...

does anybody know the exact colour matching of the existing wiring at all? i've found this site http://www.ecanfix.com/~mdhamilton/o2sensor.html which lists (what i think is) a galant of the same year model so i'm guessing those colours (down the bottom) are the right ones and i just go by that...

what i want to know is:

should i reset the ecu after doing this (to clear the "check engine" light) or should i just drive around and will it just go out?

[Rasko Da Gama]

Sorry m8, btu I can't help you :cry:
I think this is a question for kenn inn or menybrews...

I hope you'll fix that problem soon

[Oddrob]

Use your multimeter and test the O2 once its warmed up. You can test it at the ECU or at the plug. Look for the signal to occilate up and down between 0-1 volt at idle.

[bluedraco]

yeah, i think i'm going to do that to confirm whether it really is gone or not...

the problem is - how do i test it when the plug is in? you mention that i can test it at the ecu (by just putting the multimeter inside to plug on the correct pin i'm assuming) but where is that particular pin?

[bluedraco]

ok, i think i found the pin...a single green (with white stripe) wire with a white splade connector on the end...

the car was warmed up and i connected my ground of the multimeter and the positive to the splade connector...it read a very small voltage (couldn't get exact reading as my multimeter has been a bit inaccurate recently) which changed slightly...when i revved it the voltage went up (running richer) and then on deceleration it read a lower voltage...

so from that, i would say that the oxygen sensor is fine...i reset the ecu this morning and i disconnected and reconnected the oxygen sensor plug (just to make sure it was fully plugged in)...so it seems all fine...

i'll just have to see if that check engine light comes back on again...i hope not!

[Darkside]

hey guys, ya heard of Datalogger for the DSM obd1. Its kewl to have. Its tell you everything your engine is doing, you can even clear check engine light. it tells RPM, Speed, Knock, O2 reading, fuel pulse, Fuel pump, charging system, etc.... Like i say, its good to have one.

[bluedraco]

well, the light did come back on the other week...so i disconnected the new oxygen sensor and put my old one back in...i reset the ecu and over the last week or two i have put A LOT of kms on it (especially one long 2 hour drive) and the light hasn't come on...

so obviously the second new oxygen sensor is faulty, just like the first new one i had!

oh well, car is running fine with the old one back in so i'll stick with that for the time being!