blackouthx

okay so I recently replaced my 433 dollar primary O2 sensor, everything goes good for a couple days then bam my check engine lights on again but this time for the secondary oxygen sensor (low voltage) is this because im running lean/rich or due to a faulty sensor. also recently my car when driving , lets say if im in 2nd and holding it steady at 3K rpm's it will gain then loose power like in kind of a rocking motion if that makes any sense. well thanks everyone for your input on my life long problem lol

Murk 'EM

looks to me like you should have replaced both of them

97Ej6mike

I had to spend almost a week manually wiring my secondary 02 in to the ecu, because i coudlnt find the 2nd 02 sens plug on the motor harness when i did a swap. Sucked big time. And yes, they are expensive.

Rocking motion sounds like an inconsistent TPS maybe? is it a sudden jerk? or a slow pulse?

blackouthx

they sure are expensive but wtf a 400 dollars for my oxygen sensor lol yeah im gonna replace it but I was just wondering if low voltage usually means im running to rich or lean.

97Ej6mike

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blackouthx &raquo;</TD></TR><TR><TD CLASS="quote">they sure are expensive but wtf a 400 dollars for my oxygen sensor lol yeah im gonna replace it but I was just wondering if low voltage usually means im running to rich or lean. </TD></TR></TABLE>

Nah , too lean /too rich can be anything from a bad fuel mix, faulty sensor or even a busted CAT. The 2nd 02 sensor will throw a code if it gets the same readings as the primary 02 , which basically means it thinks the CAT is broken and not filtering correctly

Murk 'EM

broken? j/w how can a cat break?

SoullessJapaneseMachine

iTrader: (1)

cats don't really break...they can go bad...like if you're not tuned properly and running rich, you can 'pollute' the cat

Murk 'EM

i know.... you cant BREAK a cat .. thatd be an exhasut leak, i wanted to see his explination for a "broken" cat

Archidictus

Damage the ceramic catalyst in it with so much raw fuel or lean heat that it no longer is able to do its job.

There's your definition.

Murk 'EM

i wanted HIS defination... not everyone elses, i know how cats work i know how they go bad.. they jsut dont break i wanted to see why HE said broken

kuja396

I'm sorry I'm asking you a question instead of awnsering yours but uhh.. are the laws strict in Arizona as far as emission goes? Here in Texas, I would have converted the car to obd1 so I wouldn't have to deal with this ****.

But like everyone is saying, either its your secondary o2 sensor or its your cat. I know what your talking about with the rocking from loss and gaining of power, its probably normal, my car does it in first anyways

suspendedHatch

I love my oxygen sensor. The ECU uses is to trim the AFR under part throttle to try to keep it at stoich, which results in better reliability/driveability/lower emissions. Those are three of the main reasons why I own a Honda in the first place. W/out it, the ECU runs in limp mode which results in low power, bad mileage, parts failure, and poor driveability.

$400?! I got my AEM wideband gauge controller for $260. It works with the factory ECU.

B serious

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blackouthx &raquo;</TD></TR><TR><TD CLASS="quote">okay so I recently replaced my 433 dollar primary O2 sensor, everything goes good for a couple days then bam my check engine lights on again but this time for the secondary oxygen sensor (low voltage) is this because im running lean/rich or due to a faulty sensor. also recently my car when driving , lets say if im in 2nd and holding it steady at 3K rpm's it will gain then loose power like in kind of a rocking motion if that makes any sense. well thanks everyone for your input on my life long problem lol</TD></TR></TABLE>

$433 FOR AN O2 SENSOR?!!!!! WTF?!!!

you should have found out the source of the problem. O2 sensors go bad after a VERY long time. If it hasn't been a very long time (my car has 150k and still on orginal o2 sensor), then there must be some other problem causing your sensor to go bad. Let me put it to you this way:

You go to a doctor with a cough. Instead of finding out WHY you're coughing, he just gives you cough syrup. You stop coughing temporarily, but then after a while you keep coughing. You go to another doctor and he finds out that you have bronchitis. So he cures your bronchitis and you stop coughing.

Get what im saying? the first doctor didnt really do his job.

Your secondary sensor is a monitor only. It makes sure that the cat is doing it's job. If the cat is not doing it's job, the secondary sensor will set a CEL. So this tells you that your car isn't running right in the first place. Maybe it's running too rich and something fouled up your old primary sensor. This might also be the reason your cat is no longer functioning and your secondary sensor is setting a code. Lets say ......due to a leaking injector....or a mis fire...and so on and so on. Since your car is "rocking back and forth at 3k", there is obviously a different set of problems.

Or it's all a co-incidence and your secondary sensor really just went bad.


Either way, FIND THE SOURCE AND CURE THE PROBLEM THERE

Dont spend $433 for an O2 sensor. I dont even think dealers gouge that much for them. OEM sensors are available from parts stores for like $100-150 max. You can get universal sensors (you solder the plug on) for $65ish.

Archidictus

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B serious &raquo;</TD></TR><TR><TD CLASS="quote">$433 FOR AN O2 SENSOR?!!!!! WTF?!!!
</TD></TR></TABLE>

If he has a 5-wire, that's not a bad price. The 4-wires on most of our cars are easily had for under $100, but the 5-wire factory widebands are expensive as hell.

B serious

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Archidictus &raquo;</TD></TR><TR><TD CLASS="quote">

If he has a 5-wire, that's not a bad price. The 4-wires on most of our cars are easily had for under $100, but the 5-wire factory widebands are expensive as hell.</TD></TR></TABLE>

I would punch a baby.


Well i guess that's just more motivation to find out if:
1.) the car ran bad because of a faulty O2 sensor
2.) the O2 sensor went faulty because the car was running bad.

Ron454321

Th rocking thing is probably EACV, clean it or replace. At least thats what happened when mine was bad.

Syndacate

It's possible you running a bad primary O2 ran you too rich and "broke" your catalytic converter - or clogged it up.

Now somebody was bitching further up about "how can you break a catalytic converter" - it's quite simple - the catalytic converter is a metal shroud, with a CERAMIC honeycomb on the inside. Now ceramics are very good to heat resistance which is why they usually don't go and they're VERY hard. The only problem with being very hard is the same problem glass has - it makes it brittle. It's not really "rare" for the vibrations of the car to break the honeycomb in a few places - right now on my Jetta the honeycomb's moving around in there - sounds like twice as loud as a B16 VTEC crack at like 3800-4300 RPM. It's really not rare.

Actually, the catalytic converter is also making noise (broken) on my EJ8 - it sounds like ***.

It's also possible that while the primary o2 was bad you ran too rich or too lean and physically damaged the sensor itself (unburnt fuel in the exhaust pipe - and yes, a nearby explosion can indeed damage the O2 sensor).

First I'd look into a new secondary O2, how much is that? I'm assuming it's nowhere near what the primary is because it's not a 5 wire - is it? If that's not the issue, I'd look at the catalytic converter. Generic cats ftw.