9krpmrx8

I was just thinking (dangerous I know) and my O2 sensors have over 96,000 miles on them and the rear sensor is useless in the mid pipe. Will replacing the front sensor do anything in terms of performance/efficiency even though I am not having an issue with it? I don't think so but I was just wondering if they degrade in terms of performance over time or if they just go from one day to the next. Also, I have tried the spark plug fowler, etc. and I still get a CEL for the rear 02 but would removing it completely cause more problems? Having the CEL come on from time to time is not really and issue because it takes two seconds to clear it with the Scangauge II. Also, OT but when you disable the CEL with the AP will it still pull codes? Do people just scan periodically to see if the car is throwing a code?

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invasion08

If you are not having any problems with your front O2 sensor then changing it will not do anything.

9krpmrx8

That's what I figured.

Easy_E1

I've had one fail. And I understand that it doesn't happen very often. So if yours is working OK then you shouldn't worry about it.

The AP gets rid of the code. Over rides it. It's not stored in the PCM.

9krpmrx8

So if I'm running the AP, and say my primary O2 goes out. If I run a scan will I get a code?

Thanks for the replies guys.

Easy_E1

You will get a check engine light for that yes. And you can turn it off.

cathy521

So wonderful website!
Do not miss it!

RX-GR8 MOD EDIT: MISS THIS!

9krpmrx8

Sorry this is so difficult for me to understand. So it doesn't turn it off completely, it just allows you to clear it?

rxtreme89

from my experiences with clearing o2 sensors, they just come back on after being cleared after couple miles of driving. since your car sees the second o2 is not working properly, it will throw the cel back on to let you know. usually you can tell which o2 sensor is not working. i've had that with my last car. haven't experienced it with the 8......yet.

i haven't looked into it here on the forum but i know of 4g eclipses use spacers on o2 sensors to cut back on emissions hitting them which makes the computer think they are still running stock setups.

9krpmrx8

Yeah I clear my CEL daily now. And so far none of the tricks work on the 8 that have worked on my past cars in terms of making the CEL go away.

dannobre

If you are having mixture problems it would be worth the cost to replace it if you are running PCM based tuning. There is often a slow degradation of O2 cells over time...and they will drift

Problem is there is no reference to check it against....Unless you have another WBO2, So a new one would be the best check

Then you get into the 2 isn't really better than one argument...and really need three for a definitive answer

9krpmrx8

Yeah I just wonder if when I get the AP if I should get a single wide band O2 and get rid of the rear O2 all together. But then I wonder if there is really a great benefit to a wide band O2 on a non FI car. Maybe I will just cap off the rear bung and ditch the rear sensor and get a new front sensor.

Pico

As far as I know depending on the year, the PCM in our cars are smarter then most and can still throw a CEL even when trying to trick it.

The only real fix would be a AP (as stated above)

"If it ain't broke don't fix it"

Easy_E1

It turns off the cat failure code. That's the CEL that your seeing now.
It's because the scaling of the sensors in the PCM is wide between the front O2 and the back O2. Rich at the front O2 and lean at the back O2. It's running rich on the back O2 sensor without the cat, thus the CEL. The back O2 is looking for a leaner exhaust as it would be if the cat was there.
You will still code (CEL) with the AP if either of the O2 sensors fail.
I personally wouldn't worry about your O2 sensors. Unless your doing some serious tuning on a boosted application.

9krpmrx8

Thanks Easy.

Easy_E1

Hey I'm getting old.

9krpmrx8

Whhhah, What are you talking about old man?














Sorry just saw the BHR sig and thought flash right away.

Easy_E1

Got it quoted. Can't fool me.
Got to go it's time for my medicine and nap. But first Forza 3.
Ok maybe the medicine then Forza 3.

9krpmrx8

Haha

olddragger

piece of black tape over cel spot--works for me.
od

rxtreme89

here is what i was talking about when using a spacer on the rear o2 sensor. i know its ebay but i'm using it as an example

http://cgi.ebay.com/ebaymotors/O2-SE...Q5fCarQ5fParts

from what my friend and i did on his 4g is you plug your o2 into the nut which has a small hole to allow exhaust fumes to come thru. you clear your cel, if it comes back again then you just make your hole little bigger with a drill bit. clear the cel, if problem occurs just keep trying to resize the hole. it took us almost 20 tries to get it right but did not throw a cel after wards. i'll probably go **** seeing it since just having the thought of something else being celed and not knowing about it would eat me alive lol.

this is just a thought for some and i'm planning on buying a straight thru mid pipe soon and will try and experiment with the spacer.

dannobre

^ Won't work.......

9krpmrx8

Yep none of the old tricks work on out cars, no spark plug foulers, transistors, flux capacitors, etc.

swoope

or you can run a very hi flow cat and blow flames out of the right pipe..

with no cel!!!

the flames caught me off guard!..

beers

LytHka

Not to hijack your thread but if a cel came on for the rear O2 sensor and I cleared it and it hasn't come back in ~1000 miles does that mean it was a PCM error?

Or should I go ahead and change it as a preventative measure?