What are the 2 sensors on the exhaust ?

[Guest]

I need to buy new ones?

[Guest]

whats the car? where are they located? post up all details/rego makes it easier for everybody to answer...

could be 02 sensor or air/fuel sensor...

[Guest]

It's a 94 gt legacy and one sensor is by the sump and the other one is on the pipe that runs off the turbo any ideas what they are ?

[Guest]

Yt7629 rego

[Guest]

downpipe is definitely 02 sensor just check how many wires and get a universal X wire one or ring genuin fr the correct plug in. not sure on the crosspipe one possible egt exhaust gas temp im not sure? are you throwing codes or just want to change the for feel good factor?

[Guest]

The muppet who took my engine out some how broke them haha

[Jord]

Front and rear oxygen sensor. As said above, if you can read the model number written on the sensor you can get a brand new replacement denso or bosch unit from overseas for $150-200 landed. Genuine unit from Subaru will cost your over $600 (just a denso one anyway)

[Guest]

sounds way off for gen pricing retail on wrx 3 wire is 276 by memory. universals range from $100 up and available from anywhere bnt/repco/partmaster buy a bosch one be safe.

[tydon]

how important are the 02 sensors what if u dont have any ive been told its abit more heavier on the fuel consumption without them?

[Guest]

do you replace your spark plugs when they shit out? or your air filter when its black? change them its the right thing to do

[tydon]

 evowrx said:

do you replace your spark plugs when they s*** out? or your air filter when its black? change them its the right thing to do

my setup never came with the right 02 sensors so i just ran it with out them.... LOL woops

[Guest]

yea i cut the one off when i changed evo turbos once could have had something to with 300km at tank

[WRXONP]

Fuel consumption will be the same on boost but off boost it will rub rich and use more gas - expect surging on constant light load and erratic idle without O2 sensor

Subarus depend on the O2 for idle air fuel ratio where as nissans and mitsis don't get effected without O2 (you can disable it when tuning ecu also)

[Guest]

so how does it idle with it disabled? i thought they ran off afm cold and 02 when hot just what ive been told i have no idea personally. i have a lot to learn about engine management and everything else too...

also people sometimes get confused with air/fuel ratio sensors and 02 sensors. they are completely different but look the sme. a/f ensors are post 2000 and normally on downpipe or mani on toyota/subaru/honda. check with genuine if you are doing anything post 2000

[WRXONP]

O2 is narrow band 0-1v scale and air fuel is wide band 0-5v scale

Wideband is used for air fuel ratio on boost

O2 sensors are heated and don't work when cold - thus the signal is ignored on cold starts for the first 5 min or so

O2 signal is also ignored on wot - only used for hot idle and light load driving

I'm not sure if newer models run that great with out O2 signal but I know Ver 3 4 hunt at hot idle and surge on light load

Most people who tune the ecu or tune a link will relie on a solid tune and disable the O2 all together

*****edit

Forgot to mention the narrow and Wideband sensor work completely different

A Wideband will give a solid output per air fuel ratio - I don't know the specific values but lets say 3.5v = 13.5 and 4v = 12.5 ( not actual figures but just for example )

A narrow band will ping values to the ecu -normally 0.3 - 0.7 = stoich

So a working O2 will constantly ping values to the ecu between 0.3 and 0.7 v - when it sees 0.8v it knows the air fuel ratio is off so adjusts untill it gets the voltage swinging between 0.3 and 0.7v

A good working O2 will ping very fast - so fast a normal multimeter won't be able to display the values fast enough so u need a multimeter that has a graph or a oscilloscope to test - if she don't ping or pings slowly it's dead

[Guest]

 WRXONP said:

O2 is narrow band 0-1v scale and air fuel is wide band 0-5v scale

Wideband is used for air fuel ratio on boost

O2 sensors are heated and don't work when cold - thus the signal is ignored on cold starts for the first 5 min or so

O2 signal is also ignored on wot - only used for hot idle and light load driving

I'm not sure if newer models run that great with out O2 signal but I know Ver 3 4 hunt at hot idle and surge on light load

Most people who tune the ecu or tune a link will relie on a solid tune and disable the O2 all together

*****edit

Forgot to mention the narrow and Wideband sensor work completely different

A Wideband will give a solid output per air fuel ratio - I don't know the specific values but lets say 3.5v = 13.5 and 4v = 12.5 ( not actual figures but just for example )

A narrow band will ping values to the ecu -normally 0.3 - 0.7 = stoich

So a working O2 will constantly ping values to the ecu between 0.3 and 0.7 v - when it sees 0.8v it knows the air fuel ratio is off so adjusts untill it gets the voltage swinging between 0.3 and 0.7v

A good working O2 will ping very fast - so fast a normal multimeter won't be able to display the values fast enough so u need a multimeter that has a graph or a oscilloscope to test - if she don't ping or pings slowly it's dead

so with standard comp i can get tuner to disable 02 when i get my tune and just use afm?

i know that wideband works completely differently and u need one to tune. narrow band gauges go nuts ive seen one in a car. rest of it interesting stuff though thanks

[WRXONP]

Yea narrow bands with air fuel gauges wired to them is useless - because if O2 is working properly the gauge should allways show stoich - when realistically on boost your around the 11-12 afr and stoich is 14.7 ish

Haven't tuned a Subaru ecu sorrry but I know Ver 7s can disable sensors - not sure which ecu you have ??? With links you can configure an input to a O2 sensor but it's a waste of time - just means less tuning time to get idle / light load going nice - with O2 disabled it will take longer to smoothen the tune out but that way u have a solid tune and 1 less sensor to have fuck out when ever it feels like it

Have only played with Nissan ecus which tune off a rpm vs load table - so when O2 is disabled you just need the idle and light load cells tuned finely or ull get surging etc

[Guest]

people still do them for looks lol

yea ecutek flash99 will flash mine its v5/6.

thread hijack but what specs that evo bro? always been an evo man

[WRXONP]

Lol lol speaking of evos on here is like against the law hahaha pretty sure u can disable on a reflash -

[Guest]

we only went to wrx coz couldnt afford a roof job and they so much more comfortable for kid. missus got a gsr though and would eat the wrx any day. maybe one day ill get a evo 3... ;D any evo bits you need ive got everything to build an evo 3 engine except pistons, race bearings, cometic, eagles, race acl, arp...all sitting in my garage