Is My O2 Sensor Dying?

[rmahnovetsky]

I notice it takes a little while for my O2 sensor to work normally (I think). Here are the steps I take to make me believe my O2 sensor is on its way out.

1. warm up the car.

2. stop the car

3. wait 5 mins

4. start up the car and hook up conzult

For the first 2 mins my idle is slighly lumpy an my timming is jumming from 0 to 20 BTDC. In this time I notice in conzult that the voltage on the O2 sensor starts from 0V then jumps to .3V and slowly moves it way up to .8 volts. Is this normal does the O2 sensor have to be at a specific temp for it to work properly or is it starting to die?

After 2 mins my car idle fine. BTDC sits around 15.

Any help appreciated.

Edited October 15, 2006 by rmahnovetsky

[chrissso]

Hey. Just some info on how they work. Might help you detrmine if it's the problem or not.

The voltage should jump from about .3 to .7v and back on idle, every half a second.

It needs to be hot to work and there is a heater in it to warm it up on start. Takes approx 30 sec to warm up.

[rmahnovetsky]

Well that answers the "taking a bit of time for the sensor to work properly" .. I should hook up a cro to see if it is jumping from .3 to .7v on idle

Edited October 15, 2006 by rmahnovetsky

[cowie165]

You won't need a cro, just watch consult on your laptop.

Other than that, everything chrisso said is on the money

[rmahnovetsky]

My sensor works fine in diagnostic mode. I get my 10 flashs/ min or what ever was specified in the manual - I cant remember the exact figures.

Edited October 16, 2006 by rmahnovetsky

[rmahnovetsky]

Does it still take 30 secs for the O2 to warm up even though the dump pipe is still boiling hot. So if my car is at operating temp then I switch it off, then back on after 5 mins shouldn't the O2 sensor still be hot enough to work straight away?

anyone know, or have any idea?

[rmahnovetsky]

I guess no one was able to answer this one. Anyway I have decided to buy a new O2 sensor, probably in need of one soon anyway - 110 000 on the original sensor I think. I'll post up my finding.

[MANWHORE]

Just hook it up to consult. graph the o2 sensor voltage.

i wouldn't worry too much about the first few minutes when it's warming up. E.g. what you're looking at - like how long it takes to warm up etc, not that important.

What you want to know, is whether it's reading properly once warmed up.

No need for cro. consult can graph it. you essentially need to watch it while cruising

and you'll notice it oscillating.

Then accelerate, it'll go ultra rich.

then back off, it'll drop straight off.

[rmahnovetsky]

cheers for your input. The sensor is reading fine once the car is running. I dont have a laptop atm so I cant cruise with it logging the data . But what I'm concerned with is once when I stop the car from normal operating temp and start it up again after 5 mins, the sensor does not read properly for a minute and the temp guage is just where it was left. I would think the O2 sensor is warmed up sufficently since touching the dump pipe would burn you hand off. Maybe I have intermitent faults with it, maybe it is wearing out and it needs to be very hot for it to work. Im just plucking at straws bc I dont know the internal working of it.

Most o2 sensor cars I have been in once warmed up idles very nicely. My car idle like crap for 1 minute till the sensor starts to work. It seems funny to me as it is only my car doing this. I hope Im right as it would be nice not to waste $70.

Edited October 19, 2006 by rmahnovetsky

[rmahnovetsky]

just installed a ford el bosch sensor.. No difference.. Just for others info the sensor cost $72 at thompson spare parts in caplaba. Repco wanted $106.

I did notice my old sensor was rattled when I shook it. I read somewhere in the forums if a sensor is rattly it is not good.