Cat Converter Sensor

[zanda]

I was "observing" my cat, with the intention of upgrading to a Jap-spec on the weekend, when I noticed a sensor going into the cat. this sensor is extremely tight (no doubt because of the expansive heat and corrosive gases etc.

point is, I couldnt get it out, and therefore the Jaap-spec upgrade is on hold until I know what this sensor does.

followed the wire to under the passenger side front seat, from where I assume it goes to the computer.

Questions:

1. what is the sensor

2. what does it do

3. what happens if I cut it?

4. who do other people with the same year/model not have this *swear word* sensor?

[Guest RedLineGTR]

i have had it on mine most aftermarket cats dont have a whole for it...you can unscrew it with a spanner..its a thread type of screw. It is the the emission control systems in cars, nothing happens when you pull it out, i have just put it under the heat shield above the cat and tied it down. It just makes some calculations etc, nothin serious, can really get technical.

Have not had any problems and most people do the same, dont know about cutting it but i just hid it out of the way just in case.

[Clint32]

I wouldnt risk cutting it but removing it is no prob, just hit it with some CRC and get some locking pliers as generally normal spanners will not get a good grip and strip it due to its tightness.

[zanda]

there is a plug connection under the seat - what would happen if the sensor just "went away"

I dont hink I can get the sensor out without snapping the "screw". It's just in too tight.

[akeenan]

you can get it out. its not an actual screw its a little nut on a screw if you understand the nut should turn. crc it leave it be then spanner it off. some aftermarket cats have these holes. mine does!

[greygirl1976]

dont take it out if u own a 33 your car will go in limp mode

its called a pyrometer pronounced {pie rom meter}it is there to tell the ecu that your cat is f=?kin hot ie blocked u can take it out on a 32 coz its only hooked up to a light on the dash

[payaya]

i thought it was called the lambda sensor?

[93RPS13]

i think it is an oxygen sensor for the computer to adjust the air to fuel of the car.

[Steve]

The sensor is a temperature sensor. Removing it doesnt hurt anything - I have had mine tucked into a hole in the subframe for about 9 months, with both a stock ecu and power fc - no problems.

[browny]

It's a temp sensor (or pyrometer) on the R32's.

I will double check the wiring diagrams and ecu diagnostics I have for R32 to see how exactly its connected. From memory it didnt look like it had any ECU function and is only used for a warning light.

[Lenno]

yeah guys it;s a cat converter temp sensor...don't ask what it does but when i got my new cat put on old mate just drilled a hole after the cat and welded on a swangy fitting that the probe can slip through and done up around it...all sweet

lenno

[akeenan]

i think it is an oxygen sensor for the computer to adjust the air to fuel of the car.

hmmm woudlnt that be the afm?

what about the sensor that actually sticks through the dump pipe?

[greygirl1976]

on a r32 the cat sensor goes to the light on the dash

it does this aswell for a 33 but allso sends a signal back to the ecu to tell it that it is registing the heat in the exhaust if u take it out the ecu doesnt get the signal and puts the engine in to a semi limp mode because it cant read the exhaust heat

i kmow this coz i put a rb25t in a silvia and run like crap on boost put this sensor in the exhaust problem solved

its out of the way under the car and its there for a purpose

[ix9]

zanda,

CRC buddy, lots of it. I upgraded my cat to jap spec and replugged in my sensor. Everything is fine. I wouldnt go removing it willy-nilly tho, just leave it there. It'll come out with some crc and some time...

[Cake]

zanda, don't cut it dude, i had to cut my old sensor because for f**ksticks who did my cat for compliance welded the bloody thing on. i managed to get hold of a new sensor easily enough though. when i cut it, the cat light came on, on the dash, and stayed on all the time. it's there to tell you your cat could be blocked, but because mine was cut, that's what it was thinking. if i left the car idling for about 2 minutes it would turn itself off with this sensor cut (as greygirl1976 said, limp mode). you could just unplug it from under the seat (i don't know if this will cause the light to come on or not), or just tie it on to the cat, or just plug it in. mine is currently plugged into the car, but not connected to the "cat", just tied onto the side of it for now and its fine.

[Sydneykid]

Hi guys, in Japan it is a requirement (since the 80's) to have a warning if the catalytic converter is overheating. The sensor mounted into the cat is for that purpose. I have yet to find a car that runs any differently when you unscrew the sensor and wire it up out of the way. I have seen people clamp it to the outside of the exhauts pipe just to be sure.

The lambda sensor for air fuel ratio checking (fuel economy and emmisions control) has to be mounted much closer to the engine. This means immediately after the turbo on Skylines.

Hope that clarifies

[Cool Hand Luke]

You could just take the cat off . Mine is gutted was tested by the RTA. It came up perfect... Ive been told that the nissan engines are very good for emissions.