Jump to content
SAU Community

The Sensor Near The Cat

iwantagtr

By iwantagtr,
in General Maintenance

 Share

Recommended Posts

iwantagtr Rising Star

iwantagtr

Posted
Posted

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

Link to comment
https://www.sau.com.au/forums/topic/237825-the-sensor-near-the-cat/
Share on other sites
some_cs_student Veteran

some_cs_student

Posted
Posted
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 Grand Master

PM-R33

Posted
Posted (edited)

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 by PM-R33
hanyou Grand Master

hanyou

Posted
Posted
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 Grand Master

W0rp3D

Posted
Posted
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 Grand Master

GTS4WD

Posted
Posted

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 Grand Master

W0rp3D

Posted
Posted (edited)
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 by W0rp3D
  • 5 weeks later...
Gus- Grand Master

Gus-

Posted
Posted

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 Veteran

some_cs_student

Posted
Posted

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....

  • 2 weeks later...
hr32gts Rising Star

hr32gts

Posted
Posted

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 ?

  • 6 months later...
kwl33 Contributor

kwl33

Posted
Posted (edited)

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 by hardcorz
  • 2 years later...
PUDZ 32R Enthusiast

PUDZ 32R

Posted
Posted

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 Veteran

stig mick

Posted
Posted (edited)

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 by stig mick
PUDZ 32R Enthusiast

PUDZ 32R

Posted
Posted

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.

  • 1 month later...
iruvyouskyrine Grand Master

iruvyouskyrine

Posted
Posted

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?

  • 2 months later...
krayzie32 Mentor

krayzie32

Posted
Posted

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)

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • GTSBoy
      What brakes on R34 GTT(Europe)

      By GTSBoy · Posted

      I would just put EBC back on the "I would not use their stuff" pile and move on.
    • Duncan
      What brakes on R34 GTT(Europe)

      By Duncan · Posted

      Can I suggest you try EBC directly again and link them to as many competitor catalogues as you can to show their listing is incorrect, eg https://dba.com.au/product/front-4000-series-hd-brake-rotor-dba42304/ If you have access to an R33 GTST VIN and your VIN, you could also use a Nissan Parts lookup like Amayama to show them the part number is different between 33 GTST and 34 GTT which may get their attention
    • Kapr
      What brakes on R34 GTT(Europe)

      By Kapr · Posted

      So i got reply from EBC and they just this site where you can clearly see those 296mm fronts on R34 GTT. I send them photos and "quotes" that 296mm are not for 34 GTT and they are too small. But it will be very hard to return them cuz nobody here knows 100% and they just copy those EBC catalogue :-D https://ebcbrakesdirect.com/automotive/nissan/skyline-r34
    • 04-LOOX
      R34 GTR Vspec Garage Sale - All must go!

      By 04-LOOX · Posted

      Hi, is the HKS  Tower Bar still available ? negotiable ? 🤔
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      From there, it is really just test and assemble. Plug the adapter cables from the unit into the back of the screen, then the other side to the car harness. Don't forget all the other plugs too! Run the cables behind the unit and screw it back into place (4 screws) and you should now have 3 cables to run from the top screen to the android unit. I ran them along the DS of the other AV units in the gap between their backets and the console, and used some corrugated tubing on the sharp edges of the bracket so the wires were safe. Plug the centre console and lower screen in temporarily and turn the car to ACC, the AV should fire up as normal. Hold the back button for 3 sec and Android should appear on the top screen. You need to set the input to Aux for audio (more on that later). I put the unit under the AC duct in the centre console, with the wifi antenna on top of the AC duct near the shifter, the bluetooth antenna on the AC duct under the centre console The GPS unit on top of the DS to AC duct; they all seem to work OK there are are out of the way. Neat cable routing is a pain. For the drive recorder I mounted it near the rear view mirror and run the cable in the headlining, across the a pillar and then down the inside of the a pillar seal to the DS lower dash. From there it goes across and to one USB input for the unit. The second USB input is attached to the ECUtec OBD dongle and the 3rd goes to the USB bulkhead connected I added in the centre console. This is how the centre console looks "tidied" up Note I didn't install the provided speaker, didn't use the 2.5mm IPod in line or the piggyback loom for the Ipod or change any DIP switches; they seem to only be required if you need to use the Ipod input rather than the AUX input. That's it, install done, I'll follow up with a separate post on how the unit works, but in summary it retains all factory functions and inputs (so I still use my phone to the car for calls), reverse still works like factory etc.
×
×
  • Create New...