HEGO sensor

[gman26]

My 95 GT sends back engine codes 181 and 189, indicating a Heated Exhaust Gas Oxygen sensor problem. Where exactly is this? Any recommendations for fixing this problem?

 

[VibrantRedGT]

That would be the oxygen sensors (O2). They are located after the headers on the mid-pipe section of the exhaust system. One on each side. The 181 and 189 are lean codes. If you haven't changed your O2's in a long time it is time now. Also when I use to get those codes I would just turn up the fuel pressure a few psi. If you don't have an adjustable fuel regulator then look into that as well. It's a great tuning device.

 

[gman26]

I believe there are O2 sensor before and after the cats. Is this true? If so, how do I know which one to replace?

 

[WhiteDevil]

I believe there are O2 sensor before and after the cats. Is this true? If so, how do I know which one to replace?

NO that is not true. On 94-95s they are only before the cats. 96+ mustangs have them before and after.

 

[gman26]

Thanks for the info, this is my first Mustang.
How do you manage with all the smog laws in CA? Do you drive you stang on the street? Is everything on your car street legal?
I'm thinking about getting cat-backs and going slow from there, not sure what is legal here.
Thanks,
George