Jump to content
SAU Community

Recommended Posts

I was looking at my cat the other day, and i noticed that there is a sensor in the cat,i think its a secondary 02sensor.Anyway its been weld to the cat so if it is a 02 then im guess that it would be stuffed after the heat of being welded.Where can i get new 1 and whats it there 4.

Link to comment
https://www.sau.com.au/forums/topic/25201-wtf-is-the-sensor-in-the-r33-cat/
Share on other sites

The EGT sensor illuminates a warning light which looks like a side view of the catalytic converter with wavey heat lines coming off the top of it (looks more like a BBQ!) It will illuminate when the temperature has reached around 850 degree celcius. This is very hot, and is usually due to either driving the car very hard continuously (ie: around a race track) or if driving normally is due to an extremely lean engine conditions (not good! perhaps a lazy fuel pump?)

This doesn't affect the operations of the ECU, but serves its purpose to help protect both the turbo from excessive heat (ceramic turbines in particular) from high temp failure and also to help the Platinum Rhodium material in the catalytic converter from being heat damaged.

Heat damage reduces the cat's ability to convert carbon monoxide and other poisonous gases back to a safe (and legal) emissions standards. Most cats don't work too well after 80,000km's anyway, from what i've been told.

If you ignore the warning light, then i think you'd be taking a blind eye to a possible engine problem if the light come on when you were just driving around normally (ie: not doing laps on a track)

Hmm, could be a faulty EGT sensor, but i still think that it could be indicating an engine that is running a bit too lean. I hear stories from a dyno operator i know here that sees cars that come in every day that have been so called "tuned" or "dynoed" that run extremely lean in the quest to extract as much power as possible. He says that some performance shops tune the cars so aggressively to extract as much power as possible to impress their customers, when in reality it's better to tune conservatively on a street car taking into consideration different qualities of fuel from batch to batch, different ambient temps, etc, etc. Too many variables to consider, and you should be factoring in some reliability into the engine with some form of thermal control. (A bit richer from Stoichiometric)

Anyway, i'm rambling again, get it looked into! At least check your fuel pressure and A/F ratios, as a EGT warning is a rare instance on a street car, i'm told.

um mods where safc,fmic,9psi,hks filter hi flow muffler. 212hp or round there.They told me my exhaust is causing issue's.I think the fuel pump is stuffed to.Seeings im not driving it im saving heaps of cash and im getting 3inch turbo back exhaust,255lpr pump,malapasi reg,To4e,plenum modified like a gtr style.Cause i think the turbo is a bit tired.Ill see how that runs if it still unpowerd then wolf3d,injectors,manual.I do alot of my mods myself (still building 327hp sohc vtec civic,time for body work:)

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


  • Similar Content

  • Latest Posts

    • Hello, everyone. I'm new to the forum. I have a 1989 Nissan Skyline R32 GTR. I have lost all power to the interior, including AC controls, the gauge cluster, turn signals, and windows. Stuff that still works includes the horn, brake lights, radio, and headlights. All fuses, in the interior and exterior boxes, tested good.  It starts and runs fine, just with no gauge power or anything stated above. No warning lights either. Things that I have tested: - Fusable link tested fine - No other fuses blown - Alternator good - IGN switch tested fine - With my power probe, I can backfeed power through the IGN pin to the plug on the back of the gauge cluster, and everything comes back on.    So my theory is something on the control side that sends the ignition power through the system isn't doing its job, or a wire is broken. (I would think that it is the ignition switch that would do that, but who knows?). The ignition relays don't fire (all relays tested good). So what tells them to fire other than the IGN switch?  I would really appreciate it if someone had some insight on this. I have tons of hours into this; I don't want to give up in defeat! I have the HD wiring diagram, but having all those wires laid out like that on one sheet of paper makes things pretty hard to follow.  Thanks for reading, and thanks for the replies.  Where should I look next? Thanks.
    • Install a MAP sensor pre and post throttle. Best data you could have for NA, then play with the bends and/or air box and see how much of inflection is created at WOT on the plot.
    • And gone to a new home  
    • The car remains in paint jail. I am now pretty convinced that the whole "RB25 Airboxes are kinda limiting to ~300kw" could be a thing. Also saw a good video from Engine Masters: (Sorry for FB link) (https://www.facebook.com/watch/?ref=search&v=761771519471924&external_log_id=c10bcbb6-2c39-4ff3-9240-287e9921fde6&q=Cold Air Considerations) Where they tested Pod Filter sizes and kept adding bends to a LS3 on an Engine Dyno to find if bends caused power loss. It's a good video worth watching - They did lose ~25hp from making an intake which had 3x90's and a 120 degree. They only lost maybe 1hp with a basic 90. I feel that by sealing up my airbox I have: 1) Created the same restriction a stock airbox would have. 2) Created a very convoluted set of intake 'pipes' by forcing all the air through the ducts. So I am pretty confident I'll be going full circle and have a huge hot air intake pod and actually see a benefit. The air does *not* stay hot once it gets flowing, aided by the ducts, and the pod can then pull air from anywhere. All the posts of yore talk about the stock airbox costing 10-15kw at 300kw+ but you know what? I f**king would very much like that 10-15kw and I remember my own pod filter in engine bay experiences. Turns out the GTT Reo and Headlight brackets really don't allow you to mount GTR items, no matter what the internet says. Various brackets have had to be made up to actually make it fit right for the front bar. Also some idiot mounted a 3L Accusump right where the bumper wants to go, so that has had to be 'relocated' To where, I am still not sure, but it's supposedly mounted in the pictures and I can't see it.
    • Sounds like the oil pressure light is wired into the oil temp sensor... As it warms up, resistance on temp sensor reduces, hence more current can flow and the dash light gets brighter.
×
×
  • Create New...