The Sensor Near The Cat

[iwantagtr]

Hi I am a bit cofused.

- Do u need the sensor located near the catalytic converter or not?

- If you have an after market exhaust and cataltic converter does this sensor do anything?

- What is the primary role of this sensor?

- Some people call this sensor an o2 sensor and other people call it a heat sensor what is it?

I have read many posts and got more confused as I have read on could somebody dumb it down for me?

Cheers

[some_cs_student]

Hi I am a bit cofused.

- Do u need the sensor located near the catalytic converter or not?

- If you have an after market exhaust and cataltic converter does this sensor do anything?

- What is the primary role of this sensor?

- Some people call this sensor an o2 sensor and other people call it a heat sensor what is it?

I have read many posts and got more confused as I have read on could somebody dumb it down for me?

Cheers

FYI, I'm not an expert but I do have an aftermarket cat without temp sensor.

If you have an aftermarket cat you can get a bung (?) for the sensor to go in and put that on the cat, I chose not to and simply put the sensor somewhere near the cat, as it doesn't really do much anyway.

I believe the temp sensor relates to detecting a failed cat, if it reaches a certain temperature it flashes a warning light, possibly the engine warning light.

Its not an o2 sensor, otherwise I would probably have bad fuel economy now, my fuel economy is excellent.

I find that the temperature sensor isn't exactly *needed* for anything to work.

[PM-R33]

Temperature sensor which when gets over a certain temperature the light on the dash with a picture of a catalyctic convertor lights up. Made to let the owner know that the cat has failed and collapsed causing a blockage which in turn will increase the exhaust gas temperature.

Not an essential part and can be removed, but if you can, keep it cause it can be handy.

Edited September 27, 2008 by PM-R33

[hanyou]

Hi I am a bit cofused.

- Do u need the sensor located near the catalytic converter or not?

- If you have an after market exhaust and cataltic converter does this sensor do anything?

- What is the primary role of this sensor?

- Some people call this sensor an o2 sensor and other people call it a heat sensor what is it?

I have read many posts and got more confused as I have read on could somebody dumb it down for me?

Cheers

if your talking about the sensor that plugs into the cat, then you dont really need it. pretty much all of my cars except my current one i "had" to cut it off cause i couldnt get the sensor out lol. just use a bolt to close it up.

its a exhaust temp sensor

[W0rp3D]

if your talking about the sensor that plugs into the cat, then you dont really need it. pretty much all of my cars except my current one i "had" to cut it off cause i couldnt get the sensor out lol. just use a bolt to close it up.

its a exhaust temp sensor

I was going to change my cat on the weekend but couldnt get the sensor out so i left it till i figured out what it was for and whether or not it was required.

Would like to replace it does anyone know where i can get a new one?

[GTS4WD]

can somone please explain to me why the hell I/ECU want/needs to know the temp of the exhaust leaving the car?

Who cares?..

Further more.. why the hell do people have exhaust temp gauges!?

I been looking for so long and its shitting me!

[W0rp3D]

can somone please explain to me why the hell I/ECU want/needs to know the temp of the exhaust leaving the car?

Who cares?..

Further more.. why the hell do people have exhaust temp gauges!?

I been looking for so long and its shitting me!

As mentioned above the cat temp sensor is purely to warn you that the cat is getting hot because it has collapsed and is causing a restriction.

The exhaust gas temp i believe is related to how rich/lean the engine is running, the leaner the engine gets the hotter the exhaust gas's get, just another way of warning the driver that something is not right.

Edited September 29, 2008 by W0rp3D

[GTS4WD]

fair call then.. they do hve a reason.. thanks buddy

[Gus-]

i have a question reguarding all this.

my car...started having a problem with the exhaust temp sensor light coming on and starting to flash. from there the car becomes very sluggish if i put my foot down. i can drive it as long as it does not come on boost otherwise it will bog down wont go anywhere etc

replaced cat...nothing...

new o2 sensor.

turns out the exhaust temp sensor was missing, so got a new one of them. connected it up and it still does it.

any ideas what it could be...searching everwhere and no idea...could anything be unplugged etc??

Gus

[some_cs_student]

Many people run without that exhaust temperature sensor, so I'd look elsewhere for your issue, the exhaust temp sensor is really to detect if your cat has collapsed (ie. its getting really hot) its designed for a standard cat converter....

[hr32gts]

From what I understand and I am a mechanic ...

When the catalytic converter light comes up on the dash it sends a signal to the ECU to tell it to retard timing and I think it may also increase fuel incase of a lean out ... (Limp mode)

I have this same issue in my R32 GTS auto the cat light comes up on the dash and the car will run like total crap underpowered and bogs down etc... this is a failsafe to protect the engine ...

are the majority of the guys on here still running stock management ?

[kwl33]

diggin up an old post,

does anyone know what the voltage of this exhaust sensor should read using Datascan or similar software? I get a reading of 5volts (which is full) and it doesn't ever change, so I assume its either a) stuffed or b) not connected. can anyone confirm what the correct voltage should be?

Also wouldn't it be better to have this sensor in case of lean out?

Edited May 19, 2009 by hardcorz

[Driftation]

Yeh you will have to reconnect the nos

[PUDZ 32R]

ok i know im digging up an old post but it seemed better than starting a new one..

i installed a mines tuned ECU into my '32 GTS-t yesterday and now today driving my car around town this exhaust gas temp light is flashing on the dash basically as soon as i start the car. it flashes almost constantly sometimes and even when i am not booting it just cruising at 60kph with constant throttle. this has me worried because i know when the exhaust temp gets hot it is a sign of leaning out but this light is flashing at all driving conditions. if i just cut the wires will the ECU go into limp mode? what is worrying me is that i have heard mines tune their ECUs for 102 octane fuel and im only running 98 which is the best i can get here.

if anyone else has had this issue for any reason please let me know!

thanks.

[stig mick]

I'm pretty sure that in the r32 the exhaust temp light also doubles as a check engine light?

Which means you could have a bigger problem than a hot cat.

Also I think you can cut the sensor into the cat as it's only a temp sensor but the light may still come on if that's not the problem, dint take my word for it wait till someone else replies and corrects me if I'm wrong

Edited July 15, 2011 by stig mick

[DVS JEZ]

Is it still driving fine? Cat light can mean limp home mode if there is an issue.

[PUDZ 32R]

yeah its still driving fine! thats whats confusing me. i know it could mean limp mode but it still has the same amount of power as normal . it also didnt do it all day today?? WTF!! im thinking im just gunna cut the wires.

[iruvyouskyrine]

My check cat light has come on after putting a decat in. Before that i only had a 100 cell cat in. Thing is when replacing the cats i didnt see any sensor connecting to the cats. There was one sensor on the dump pipe right up near the turbo but i believe thats the O2 sensor? The dash light is constantly on from as soon as i start the car. I havent notice performance decrease at all, so that means the engine isnt running rich and in limp mode?

[krayzie32]

Anyone able to answer the above, just installed a fresh rb25 in my 32gtst and noticed backyad mechanic who done the previous 25 cut the cable and put in decat. As he was unable to remove egt sensor from cat.

Now my problem is its a solid light...

Does that tell me engine is knocking or very lean cos it feels, sounds & drives fine on and off boost, (im running completely stock 98 s2 rb25, with all ancillaries, gt2530 turbo & s2 std 5spd ecu)

[krayzie32]

^^ additional to the above, if egt sensor has been cut and wires loose does open cct cause the light to stay on?