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

    • Has equal chance of cleaning an AFM and f**king an AFM. I think you can work out what happened. When the Hitachi ECU sees the AFM die and goes into the associated limp mode, then it will start and run just fine, because it ignores the AFM and just runs on idle maps that will do what it needs to get it going. But there is no proper load signal, so that's about all it can do. My suggestion? If you don't want to go full aftermaket ECU, then get some R35 GTR AFM cards and some housings to put them in, in the stock location, and Nistune the ECU. Better to do a good upgrade than just replace shitty 40 year old tech with the same 40 year old tech.
    • So my car was recently having trouble starting on initial crank, I would need to feather the gas for it to start up but besides that it would start and run fine. So I clicked the idle air control valve (with throttle body cleaner) and cleaned the MAF sensors (with MAF cleaner). The start up issue was fixed and now the car turns over without the assist of the throttle, but the car is in limp mode and wont rev past 2.5k RPM. From what I understand the IACV would not put the car in limp mode, so I am to believe it is the MAF sensors, but it was running fine before and now I cant get it out of limp mode. I cleaned the MAF made sure the o rings were seated properly. Made sure the cables were plugged in properly, the cables also both read the same voltage. Does anybody know why this is or what could be causing this or how to get it out of limp mode?
    • Ooo I might actually come and bring the kids, however will leave the shit box home and take the daily
    • Thanks. Yeah I realised that there's no way I'd be able to cover the holes with the filler, it would just fall through. Thanks again @GTSBoy!
    • That was the reason I asked. If you were going to be fully bodge spec, then that type of filler is the extreme bodge way to fill a large gap. But seeing as you're going to use glass sheet, I would only use that fibre reinforced filler if there are places that need a "bit more" after you've finished laying in the sheet. Which, ideally, you wouldn't. You might use a blob of it underneath the sheet, if you need to provide some support from under to keep the level of your sheet repair up as high as it needs to be, to minimise the amount of filler you need on top. Even though you're going bodge spec here, using glass instead of metal, the same rules apply wrt not having half inch deep filler on the top of the repair. Thick filler always ends up shitting the bed earlier than thin filler.
×
×
  • Create New...