Mazda Rotary Club

Cars by Model Type => 2nd generation RX-7's => Topic started by: grinder on July 15, 2010, 12:39:12 PM

Title: JDM Cat heat sensor help
Post by: grinder on July 15, 2010, 12:39:12 PM
Hiya chaps

whilst it was my birthday and i was on leave from work , i thought it a good time to get the car de-catted

so after spending hours trying to get the bolts of the exhaust at the turbo - i finally did it

BUT .. there is a heat sensor that plugs into the cat .. the bolts were rusted as hell , so tried with a 10mm socket - nope , tried with a 9mm hammered on and nope - so ended up snapping the sensor off ( there isnt one on the replacement cat - so its not needed )

out of interest - whats the down side of what i have just done ???

is the ecu going to think that something has gone wrong - or should i just get a cat light on the dash ??

Cheers chaps

Stu / Grinder
Title: JDM Cat heat sensor help
Post by: m1tch on July 15, 2010, 05:44:27 PM
Wouldn\'t it just throw an error code in the ECU and maybe the heat light will come on? are you sure its a cat sensor, and not the O2 sensor!
Title: JDM Cat heat sensor help
Post by: Prof on July 15, 2010, 06:21:47 PM
There was a heat sensor switch near the cats - but I didn\'t think it was bolted to them.  I think all it does is to stop injecting air into the cats / exhaust if the temperature goes over a certain point, to avoid turning the cats into glowing red fireballs !
 
But as Mitch says - you defo sure it\'s not the o2 sensor you\'ve mullered ? :Giggle
Title: JDM Cat heat sensor help
Post by: m1tch on July 15, 2010, 11:20:02 PM
Mitch suggests plugging in a wideband O2 and run an aftermarket ECU :D
Title: JDM Cat heat sensor help
Post by: L18M on July 15, 2010, 11:51:43 PM
after this sticking in my head for the past few hours.. i do remember my cat having a sensor going into it.
i didnt notice anything different once i decat and thats with a stock ecu (chipped).
Title: JDM Cat heat sensor help
Post by: grinder on July 16, 2010, 09:34:07 AM
trust me - i know what an 02 looks like !! - thats up near the turbo !!

this was at the opposite side of where the air pipe enters the cat

i will see what happens when i evenually get it all rebuilt - the exhaust is still wedged under the car at the moment - and with the horrible weather - it can stay there :D :D
Title: JDM Cat heat sensor help
Post by: papercutout on July 18, 2010, 05:40:21 PM
I\'ve got a stock cat outside that came off my car, I can vouch that it has no sensor in the side of it.

I have a UK spec car.
Title: JDM Cat heat sensor help
Post by: grinder on July 18, 2010, 09:07:56 PM
mine is a JDM

when its off i will take some pics :D
Title: JDM Cat heat sensor help
Post by: najiru on July 20, 2010, 12:25:40 PM
Not sure if this helps but with the temp sensor on my FD I removed it when I decated and then just linked the wires together to stop the heat light coming on on the dash. That was with a power fc though.
Title: JDM Cat heat sensor help
Post by: grinder on July 20, 2010, 12:58:24 PM
cheers mate - i have to get it all back together yet - and then i will see what happens

this bloody weather is making it bloody hard - might be 3 weeks before i get the exhaust OUT from under the car :(
Title: JDM Cat heat sensor help
Post by: pdtaylor18 on July 20, 2010, 09:03:17 PM
I know exactly the sensor you are talking about and it seems is just fitted to JDM cars. I assumed its only a heat sensor as mine is still connected electrically but just tucked out the way.  This may well be a heat sensor as you said and I can again only presume that this sends a signal to the ECU. The other hear sensor is under the seat and i think its that that puts the \'heat\' sensor on the dash.  I have not had a single problem with \'warnings\' when these are disconnected/not attached either on a standard ECU or standalone.
Title: JDM Cat heat sensor help
Post by: grinder on July 21, 2010, 11:56:11 AM
thats great news Pete !!

mine was that rusty i couldnt get it off - but whilst bending the sensor to hammer a socket on - it became weak - so a few more bends saw it coming clean off ;)
Title: JDM Cat heat sensor help
Post by: papercutout on July 21, 2010, 07:50:13 PM
Quote from: pdtaylor18;705854The other heat sensor is under the seat and i think its that that puts the \'heat\' sensor on the dash.  I have not had a single problem with \'warnings\' when these are disconnected/not attached either on a standard ECU or standalone.

That\'s on my UK spec car too, I always wondered what it was! \'Junk\' is the answer then :p
Title: JDM Cat heat sensor help
Post by: grinder on July 22, 2010, 10:36:04 AM
well the exhaust is off .. whoohoooo

dragged it onto the patio and split it apart ( and it was SOOOOOOOOO easy - the 4 nuts on the cat came off without any problems )

just need to get some pics off this sensor thingy and work out the best way to put it all back on the car now :D
Title: JDM Cat heat sensor help
Post by: papercutout on July 22, 2010, 05:29:05 PM
*cough* decat.