im working on a project with my second o2 sensor, the one after the cat... i need to know which wire is which.,... ground, positive (12v), and signal.... also if we have one, the heater wire... thanks in advance

 

please don't tell me you're hooking up a narrowband a/f guage...

off the top of my head... there should be 2 white wires, a black wire, and a grey wire. The heater wire will be one of the white wires. I don't remember which is the signal wire(black or grey) but if you take a voltmeter to it you should be getting a voltage at around 2.5 volts(we're on a 0-5v system) in open loop.

 

black is ground, grey is the signal wire, white's are the heater and power wire to the sensor

but that is for the AFR guage being hooked up to the 02 after the cat, before the cat the signal wire is blue

i would sagest getting a wide band guage and sensor and have a local muffler shop weld in a bonge for it BEFORE the cat. After the cat you are getting reduced AFR read's since the purpose of the cat is to scrube as much fuel as possilbe out of the AFR to reduce emissions going into the atmousphare.

 

assumptions(sp) only make an ass of u and me lol...... no im working on an o2 simulator

how can i tell what is power and what is heater?

 

lol ok. just making sure.

well power will be 12v. the heater wire won't but it'll have higher amperage.

 

so the wire that has 12v is power.... the other wire will throw a diff voltage? and thats heater? is this while the car is running?

 

yes while the car is running, but that is for the o2 sensor that is after the cat, if that is what you are looking for.

 

open or closed loop matter? and is this heater wire something special? if i cut it on accedent i can just re-soilder it back together, cuz the best way for me to do this would be cut one white one and then pos to ground with my multi meeter... if i see 12v then its power if not than its heater, but i need to be able to put the heater back because only the other 3 need splicing... any idea how many volts the heater should throw

 

you dont even have to do that, they make these special probes that come with most multi meters that puncture right into the wire without cutting it. thats how i tested my fuel pump on my old car to find out that it was bad

 

ya thats wut i got i guess ill use em, just that being in an auto trade school their trying to get us to not do it because being under a car it can actully corrode inside the wire but i can electrical tape it.... b/c there arent any real connecters i can backprobe....

thanks for the help

 

oh yeah, forgot about that, lol but you would still have to use electrical tape to weather seal it after you spliced em back together, or used heat shrink for wires.

 

ya that hit me right as i read this.... lol not on top of my game ive had food posioning since sat night

foodpoisioning> me

pos rep for u

 

cool back at ya bro

 

do our cars cut the 12v power once the heater element is warm enough?

 

12v is all times. Heater I'm not too sure what voltage it runs. open loop or closed loop

I went to UTI and they teach us all that crap about corroding the wire and everything too. It's a bunch of bullshit. I've done it thousands of times on my own cars and I've never had a problem with the wiring corroding. Put some electrical tape around it afterwards if you're really worried about it.

 

got it all hooked up 30 mins later threw sensor circuit voltage too high.... so im guessing ive got too much resistance idk, i emaild the company that made the simulator, their a good company theyll prob hit me back mid tomorrow

 

what voltage is the simulator sending? The input should be dead smack in the middle of the voltage scale. The ecu looks for a certain signal and throws a code if it's too high(rich) or too low(lean).

If it's saying it's too high you probably don't have enough resistance. You need to lower the amount of voltage being sent.

 

idk its 11 pm ill look tomrrow... probe the signal wire? on V on the meter right?

and ground out to a bolt..... sry i always question myself with electrical stuff.... the one thing UTI never taught me enough about

 

you're looking for dc voltage. I'm like 70% sure we're on a 0-5v scale so it should be around 2.5v. What kind of voltmeter do you have? It should have a quick adjustment rate so you can see if the voltage dips or raises on you for short periods of time.

What campus did you go to? I just graduated out of the phoenix area in the mercedes program.

 

glendale heights IL ..... i have course 26 and 36 left, then i might head to pheonix for MMI/harley davidson

 

eh. I'd check into some different campuses for mmi. Phoenix is literally the ******* of the U.S. A hot, sweaty ******* with a bunch of brown turds runnin around.

 

dont waste your money on the MMI for what "15000-18000 cost of schooling for what 10-11 a hr. dont waste you time man. i am PHD cetified from harley, and i went to yamaha for for money and better beifits. im now all street bikes crusers and 4-whellers plus rangers- polaris and there line ups you are better off starting with no exp. and asemble bikes and others with manuals there go from there its the same but cheaper and if you want do in dealership training for free.

 

I agree. The only thing I really got outta going to UTI was my mercedes cert and I've got hours of actual mercedes experience. But you gotta pay extra for that, it's not even included in the main program. The whole thing felt too rushed for the money that was sunk into it. You get things you wouldn't normally get going through a school like mmi or uti instead of dealer training but it's just not worth the money if you're paying for it out of your pocket.

As far as getting a good job as a tech in a mechanical industry experience>school any day. You would actually probably learn more just buying a hayne's manual and the corresponding vehicle and just start taking it apart and putting it back togeather. Probably cheaper that way too. I swear they just have a bunch of guys in the back of the school just copying pages out of a hayne's manual for lessons. It's the same ****.