Hey all

 

Put the straight through 2.5" stainless system on the 300zx TT and had the cats taken out. Problem is i left the car for a while and they binned the CAT sensors and cut the wires to them because i hadnt left instructions with them of what to do?!! FU**WITS

 

Anyways went to Nissan to try and find a new pair of 02 sensors and they supplied me a pair that looked nothing like the ones that were on the car!!! they supplied the ones that are supposed to be on uk and Jap spec models (after taking my chasis no) and they arent the ones. mine have two wires on each 02 sensor and the ones they supplied have three wires on each. wouldnt mind cutting and joining but dont know if these are the right ones and where the third wire would go.

 

Below is the unit that the sensors would have plugged in to. its located under the centre console in the car right where the armrest/compartment is. when this is unplugged no ECU light comes up and the car still runs fine! the silver braided wire covers run under the floor plan and in to where the CAT would have been.

 

Thanks all for your time.

PS sorry for the big picture. and thanks to those who are helping!!!

 

[This message has been edited by Latz (edited 08-11-2001).]

how to post pictures on ubb's 101

 

 

[ i m g ] img is short for image

 

 

so example [img.]http://www.yourZpicture.jpg[/img.]

 

remove the period

The O2 sensors are in the turbo manifold not the cats. What they have removed is the cat temp sensors. These should be removed and tied up somewhere safely, not cut off.

So looks like you'd better take the O2 sensors back, or flog them to someone who needs some spares. How much were they ?

yeah those are cat sensors, you dont need them, well i got rid of mine

 

Thanks KSZX and ANDYP and Warren and Johnny for all your help so far.

 

Andy, please take a look at the piccy i posted and tell ,me if it rings true with what you're saying.

 

Where are the 02 sensors accesible from? when i take the turbos off in a couple of weeks will i see them then?

 

i paid 200 for the pair!! what a wa**er!! i have never had one of these before. i used to be a Vauxhall man and could tell you all about them but not these!!! on the vauxhalls they have the 02 sensor on the bottom of the downpipe. just assumed thats what it was!!!

 

so do i just buy new cat temp sensors, connect them and hide them under the seat?

Fraid I don't know what the thing in the picture is. I can see my O2 sensors from underneath on the manifold that connects to the downpipe. From what I remember they look like small bolts with a wire sticking out. Dunno exactly where the wire goes after that though.

 

Not sure about replacing the temp sensors though. Don't think they'll actually do anything, but you may have the warning light on all the time. If you do then maybe you could remove the bulb !!!

 

[This message has been edited by AndyP (edited 08-11-2001).]

Thanks so much AndyP

 

Appreciate your help very much.

 

Johnny, do you want these mate? i'll bring em up to ya when i see ya?

 

Hmmmmm O2 sensors I had one of these go on my car and can confirm they are a real bitch to get to. One is down under the aircon pipes on the exhaust where it bends downwards to go under the car after the turbo. The other is directly under the brake master cylinder, again on the exhaust as it bends downwards. What has been removed are the cat temp sensors. These could be replaced with resistors Basically the cat temp sensors are a resistance that varies as the temperature changes - if you emulate the value of normal temp with a resistor then the light will go out. Does anybody know the resistance of the temp sensors at normal operating temp???

 

Will do some more research for you....

 

CheerZ,

 

Andy

Thank you very much andyduff. Hey you very nearly got a phone call off me!!!! courtesy of johnny boy of course.

 

if you could find out the resitance values for me that really would be cool mate.

 

Thanks!!!

Great idea Duffo.

 

According to the manual the resistance of the Exhaust Gas Temperature (EGT) sensor should be 85Kohm +/- 10% at 100 degC.

 

This has always confused me slightly, is that the sensor that lives in the Cats ?

thanks andyp.

 

yes that sounds like the one mate. i think thats what johnny was sAying to me earlier on. thanks for the info. is that the right exhaust gas temp though for when the car is running? i wonder.

 

I wonder what the EGT sensors do engine running wise? does anyone know?

 

Thanks

It is just slightly confusing because there is an Exhaust Gas Sensor, which I believe we normally refer to as the O2 sensor and then there is the EGT which I think sits in the cats and checks the temp to see whether fuel is being chucked into them, igniting there and overheating them. As far as I know this has no input to the ECU and just sets off the warning light on the dash (mine is orange and looks like a smoking fryingpan, but the colours seem to vary a little between models).

 

I reckon that if you just wire in an 85Kohm resistor, say 0.5W, then you should be on to a winner.

Thanks andy. did see that light comming up when the cats were in. it started missing at the same time and top end would be seriously reduced. this still happens every now and again (apart from the light). any ideas oh wise wizard?

 

Thanks

That is a lack of spark - bad connection to the coil pack or bad coil pack itself. When are you heading up this way??? Could have a look at johnny boys if you want...

 

CheerZ,

 

Andy

 

BTW It wouldn't matter if the resistor was the same value as the sensor reads at cold - just as long as it isn't the same as the resistance as when its overheating

 

cheers andyd

 

I will be up there as soon as i have fitted the new turbos in a couple weeks most probs. johnny boy is waiting for them to come to him first. then hes gonna send then down to me and i'm gonna fit em.

 

i thought that could be a dodgy coil pack but wasnt sure. would love for you to hav e a look matey? go out for a drink after? on me of course.

 

is there any way to check the coil packs? resistances etc?

 

Thanks

Problems with the coil packs are usually down to bad connectors on the tops. Resistance for primary should be 0.7 ohm, secondary 8 ohm.

 

All this guff is in the online manual (if you're patient). Link in the Tech Sec.

thanks andyp been much much help. will check that out and let you know the results. don i close this topic now???

 

Latz

Nah, it'll die naturally ! LMAO