alright so i installed my new buschur O2 housing today and durring the process i had to cut the O2 sensor wires (im doing more than just an 02 housing swap, im replacing the whole exhaust system from the headers back) anyways, i guess while i was pulling the turbo assembly out of the car i didnt pay attention to the wires so now that im ready to put everything back together, i see that there is a white wire, a blue wire, and 2 black wires coming off of the O2 sensor. now that im reconnecting the wires i was just wondering whether or not both black wires coming from the O2 sensor are ground wires, and if so are they going to a common ground, if so that means it doesnt matter which black wire i hook up to the severed end.

also, upon removing the O2 sensor, i got quite a bit of WD40 on the actual sensor, i was wondering if this will screw the sensor up?

you know there are plugs so they just unplug?!?

exacty... if you remove the sparkplug cover you'll see the plug that you disconnect for the o2 sensor

According to the service manual there are 4 different color wires. Only one should be black.

http://www.ne-evos.net/data/2006serv...ual/Wiring.pdf

2 are black, both are grounds..... doesnt matter.. i had to cut mine cuz it was fused to my housing.. thats how i know... or u can go to oxygensensors.com and get one for 70 bux like i had to do.

yup you need a new sensor. once you cut the wires, even if u think you did a PERFECT job re-conecting them you still have increased the OHMS in that wire and now your computer will get an inacurrate reading throwing a CEL. get a new sensor.

de de deeee, yea i guess i am a real tool for cutting it. thanks for the quick responses!

don't worry about it man. everybody makes mistakes and this site is real good for stuff like this. keep posting on evoM

i am gonna have to cut my rear one since the damn stock one wont come off.

Yea I'm looking to replace my exhaust too and came across this thread. I know you can unplug this o2 from underneath the passenger seat, but since you're saying we shouldn't cut the wires, do you know where to get an o2 with the long wire and connector prewired?

^from the dealer or various sites. an easy way to get around the rear o2 sensor is to have your ecu flashed and disable the rear o2. thats what i did.

HYTEK369.... if u can't unscrew the o2 out of your stock pipe then i sugest you just remove your pasenger seat and unplug it. then you already have your seat out so you can replace your sensor with a new one. DON'T try and cut and splice o2 wires as stated above

Black wires don't matter. When I couldn't get my stock O2 housing, I just bought one for cheap for oxygensensors.com then upgraded the O2 housing. Cut, soldered the wires with no problems. I got into an accident and broke my wires for the rear one. Soldered them up with no issues. If you can't solder well pull the wire harness off, but it can be a pain.

the stock ones are too expensive to replace. i am gonna try and solder one on like whoang40

my back one went out and i bought the bosh universale and it still sets off the ce, good to see the reason why guess i have to suck it up and ship more cash to the dealership

soldering and o2 sensor wire rarely ever keeps the cel off and if it does stay off who knows if your computer is getting an accurate reading. soldering most wires is fine but went it comes to a persice signal that the computer is trying to recieve to provide adaquate fuel its not worth trying to save 100 to risk an engine.

i know saying u may blow ur engine is quite a strech however what if ur solder conection causes the wire to drop a few volts or amps across it. now ur ecu is going to recieve a constant improper signal.

replace sensor