no o2 sensor
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no o2 sensor
i live in alberta and the emssion control here is still very laxs. so i was wondering if the O2 senor was a before or after the first cat
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As far as I know only OBD2 (96+) cars have a second O2 sensor after the cat. It's specifically to tell the ECU if the cat is doing it's job or if it's gone bad. Doesn't have any effect on the engine like the first one does.
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Actually from what I've read, on newer OBDII cars the the post cat O2 sensors main function is to check catalyst efficiency/threshold, but it also has a small effect on Total Fuel Trim.
93'TLegWag171k StockBlock,TD05,HallmanMBC,530cc,Walbro255,shortram,LWpulley,DIS-2,MSDcoil,cxrFMIC,trans cooler/external filter,WRX wheels/brakes,CES w/Borla muffler,QTP elec cutout,REVchip2,KYB GR2,GroupN tops/all fr bushings,STImounts,GSD3 tires,LM-1,etc
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Not sure of exact year, I think it's different from manufacturer to manufacturer but I was speaking generally of the newer ob2 cars 2000-up and also CAN. Personally, I treat all O2s (pre-post) equally, and would replace any I suspect are bad.
Since the car is a 1994 Turbo Legacy you only have 1 O2 sensor and it is right after the turbo, before the cat, and is accessable from under the hood.
Since the car is a 1994 Turbo Legacy you only have 1 O2 sensor and it is right after the turbo, before the cat, and is accessable from under the hood.
93'TLegWag171k StockBlock,TD05,HallmanMBC,530cc,Walbro255,shortram,LWpulley,DIS-2,MSDcoil,cxrFMIC,trans cooler/external filter,WRX wheels/brakes,CES w/Borla muffler,QTP elec cutout,REVchip2,KYB GR2,GroupN tops/all fr bushings,STImounts,GSD3 tires,LM-1,etc
This recent post may be of interest http://bbs.legacycentral.org/viewtopic.php?t=43096
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Re: no o2 sensor
sorry for the thread jack, but i have a 94 NA and i have 2 o2 sensors, whats the second 1 for?
Re: no o2 sensor
The second one would be for the ecu can tell if the cat is working. I believe it takes the reading from the first one and then compares it to the second on.
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Re: no o2 sensor
so with no cat, that's probably pretty useless. So is there a way to get rid of it, without setting off the check light?
Re: no o2 sensor
If it's a 94 Legacy, there should only be 1 O2 sensor. If it's running the stock ECU, there's not 2nd O2 sensor or cat monitoring on the OBD1 computers.
Josh
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surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm