jason007

hi
i'm missing my o2 sensor after cat, is there anything i can use instead of the oem sensor, that tells the ecu that the sensor is plugged in and that the engine's running fine?

darkclark

there are things that mimic o2 sensors but you should really replace it. you can probably get a bosch replacement sensor from the parts store if you dont want to drop the cash for oem but faking out the thing that make your engine run right is a bad idea

electron_si

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by darkclark &raquo;</TD></TR><TR><TD CLASS="quote">there are things that mimic o2 sensors but you should really replace it. you can probably get a bosch replacement sensor from the parts store if you dont want to drop the cash for oem but faking out the thing that make your engine run right is a bad idea</TD></TR></TABLE>

the bank 2 cat will not make your car run bad!

dont spread false information.

jason007

its not running bad but the check engine lights on, i heard of something called a simulator or something would that work?
and where could i find it, i looked in ebay but i didnt find it.

B serious

iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jason007 &raquo;</TD></TR><TR><TD CLASS="quote">its not running bad but the check engine lights on, i heard of something called a simulator or something would that work?
and where could i find it, i looked in ebay but i didnt find it.</TD></TR></TABLE>

you can get a universal O2 sensor for like $50 from autozone or something. I'm pretty sure sims cost more.

ARMYGREEN96

i have the same problem but i have a b18b with no after cat o2 sensor i gives me bad minage and the idle is high about 1.5k

B serious

iTrader: (1)

^^ The aftercat sensor does not affect fuel mileage or driveability. It is only there as an emissions monitor. There are other things wrong with your car. The 1.5k idle is a clue

ARMYGREEN96

what can it be if its not the o2 sensor

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iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ARMYGREEN96 &raquo;</TD></TR><TR><TD CLASS="quote">what can it be if its not the o2 sensor</TD></TR></TABLE>

about a billion different things man. There's a ton of other sensors and doo-dads on the car. The O2 sensor isnt the only thing that controls fuel curve. Your check engine light is most likely on. Why is there no after cat O2 sensor in the first place?? Have your codes pulled via a scan tool. Computers are smart. They can tell you what's wrong with them so you know where to start looking.

The coolant temp sensor
The MAP
The TPS
The IAT
The PRIMARY O2 sensor (before the cat. that's the one that controls fuel curve. It is the major contributor to fuel curve info to the ECU.)
The ECU itself
Those are some of the sensors or electronics that could be a problem.

There could be a physical problem as well:
The fuel injectors themselves (too big for the ECU's fuel map = too rich. too small for the ECUs fuel map = too lean)
Fuel pressure
Fast idle thermo valve (although, this usually causes a surging)
Vacuum leak
Throttle stop screw too far adjusted
Idle incorrectly set
etc. etc. etc.

ARMYGREEN96

wheni hooked up the computer up to the car all it says is about the heat sensor

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iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ARMYGREEN96 &raquo;</TD></TR><TR><TD CLASS="quote">wheni hooked up the computer up to the car all it says is about the heat sensor</TD></TR></TABLE>

You mean O2 sensor heater? Primary or secondary?

You could also have something wrong mechanically that the ECU does not monitor. That doesn't leave much for an OBD2 car. Maybe a FITV or too high fuel pressure/car getting too much fuel some other way. Maybe the idle has been messed with as well.

ixoiiiiviviiivi

I have a similar problem except with a 99 dx with a Si swap. As you know the dx has both O2 sensors plugged into the main engine harness, but the Si only has one. is there a O2 sensor plug in the dx dash harness like there is in the si?

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iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ixoiiiiviviiivi &raquo;</TD></TR><TR><TD CLASS="quote">I have a similar problem except with a 99 dx with a Si swap. As you know the dx has both O2 sensors plugged into the main engine harness, but the Si only has one. is there a O2 sensor plug in the dx dash harness like there is in the si?</TD></TR></TABLE>

...just lengthen the wires on the DX harness......

ixoiiiiviviiivi

I am using the Si Engine harness, not the dx engine harness. The si harness only has one plug for one 02 sensor. What i am wondering is if there is a plug in the dash harness for the 2nd 02 sensor like there is in the Si dash harness?

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iTrader: (1)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ixoiiiiviviiivi &raquo;</TD></TR><TR><TD CLASS="quote">I am using the Si Engine harness, not the dx engine harness. The si harness only has one plug for one 02 sensor. What i am wondering is if there is a plug in the dash harness for the 2nd 02 sensor like there is in the Si dash harness?</TD></TR></TABLE>

No probably not. Just take a plug from your DX harness, plug it into the secondary sensor, run the wires into the ECU cover panel area, and hard wire it into the ECU harness yourself. Done and done.

97Ej6mike

secondary 02 is STRICTLY for emissions, it affects NOTHING else. End of story.
I had to hardwire not only my second 02 sensor by hand, but my new EVAP system as well that the P2P ecu reads after my motor swap. Ive been planning to do a DIY writeup on how to go about it, its not incredibly hard, just somewhat time consuming.