wtf is the sensor in the r33 cat??

[zanda]

I asked this question a while back....as a prior to getting a jap-spec cat.......

the sensor is supposed to detect if there is a blockage in the cat - such as excessive carbon build up in the cat pores - which would stop it flowing and cause a build up of heat.

It such situations (i.e. - when the cat light comes on) the computer goes into a limp mode to help you get to the next garage.

if your cat light is coming on, it's probably either because your cat is rooted, or because welding the sensor has fuXXed it.

I suggest you look into it either way, as your car will be running well below par.

[Bo0sT_JuNkY]

i thought that it would throw the car into limp mode..hmmm well ill c how i go when i get my exhaust ill just zip tie on the body .If it still lights up then ill get a new 1 .Any idea where u can get these from??

[Zensoku]

Sorry guys, but you are both WRONG..

the EGT sensor ISN'T connected to the ECU in ANY way...

There is no way it can illuminate the light on your dash and cause your car to go into "limp mode". The EGT has a switching module which is earthed and a powered by a positive switched ignition feed. This module illuminates the light on the dash which is also earthed. The module is set to illuminate the light on your dash at around 850 degrees celcius...

On some more sophisticated ECU used in late model BMW's, Mercedes, etc, etc this is the case, but the skylines only take refenences from sensors, such as CAS, AFM, WATER TEMP, AIR TEMP, KNOCK, VSS, O2 & TPS in their Fuel, Ignition, Timing maps.

The light illuminating for no apparent reason, (all tuning aspects have been checked and OK) would either be a faulty EGT, module or a short circuit somewhere.

[browny]

My R32 owners manual shows that the egt signal is connected to pin 32 of the ecu - but its only to the check lamp and there are no ecu functions that are controlled.

The last time we covered this someone mentioned that on the R33's the ecu checks if the sensor is connected otherwise it will enter limp mode (but the actual signal isn't used by the ecu).

[Guest RedLineGTR]

if ya cat if ****ed then you'll be throwing flames out of ya exhaust...heheh then u will know...

[Cake]

when i got my car the temp sensor was welded to the cat, so when i changed my cat to a hiflow one, the exhaust guy cut it, and this made the light on the dash stay on all the time. if i left my car idling for longer than 2 minutes or something the engine would switch itself off. i then got a new sensor and screwed it into my new cat, light off, and all good.

[Zensoku]

It appears that a reproduced circuit diagram i have got of the R32's shows that the EGT module is ONLY connected to the warning light.

hmm,

Browny's comment has prompted me to have a look at a genuine Nissan R32 workshop manual and the EGT module has an output which Tee's into both the warning light and pin 32 of the ECU.

I was puzzled for awhile there, and i stand corrected.

As for a "limp mode"? I still believe that there is no such thing on the R32's, as there is no diagnostic for this.