O2 sensors???

Hey i just wanted to know if O2 sensors are mandatory in a car? I have an 87 GT with an EFI 351w in it. The idle is kind of rough (drops and surges once in a while) and i was wondering if it was because i dont have the O2 sensors plugged in. Is there any sort of adaptor that can bypass the sensors? Thanks [img]/phpBB/images/smiles/icon_tup.gif[/img]

Oxygen sensors measure the fuel mixture by how much a heated wire cools down. You absolutely need them for an early single sensor system like yours.

Later models use 2 sensors, one pre and post cat, (not one in each pipe, those are still considered single) and the second basically reports the efficiency of the cat, THE PRE AND POST CAT OBD-2 you can bypass with a replacement with the proper resistance, but you cant just cut them off (and even with that, only the second one can be bypassed)

With yours, with no O2 sensors connected, the system is just running off a fail safe memory and HORRIBLY inefficient in both performance and emissions. You probably have 35-50 horse you are giving up and driveability must be horrible

Basically, your computer is useless and is not adjusting fuel mixture or timing because it has no idea whats going on. You have to get the O2 sensor

<font size=-1>[ This Message was edited by: My427stang on 11/6/04 12:35pm ]</font>

yeah, exactly what the smart guy said!
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have to agree there, my EFI 89 ran like crap for a long time, replaced the tired stock ford O2's with some bran new bosch ones ( $90 pair ), car ran like a champ, one of the biggest reasons i converted to carb was so i wouldnt have to deal with the 101 sensors in a ford efi system that can make your car run like crap just for the hell of it.
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On 2004-11-06 00:20, torqueman0 wrote:
Hey i just wanted to know if O2 sensors are mandatory in a car? I have an 87 GT with an EFI 351w in it. The idle is kind of rough (drops and surges once in a while) and i was wondering if it was because i dont have the O2 sensors plugged in. Is there any sort of adaptor that can bypass the sensors? Thanks [img]/phpBB/images/smiles/icon_tup.gif[/img]
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Is it still or Mass Air?




BTW are you running a chip or has it been tuned?
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On 2004-11-06 00:46, Luv70sFords wrote:
yeah, exactly what the smart guy said!

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Yeah... I agree with what he ^^^ agreed to...[img]/phpBB/images/smiles/icon_wink.gif[/img]
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