o2 sensor worthless to tune with ?? help plz

[EclipseOwner95]

I did a pull today, 3rd gear , 3k-7k, at 3k timing was 14 degree's, o2 voltage .82 ( already pretty lean ) 0 knock, 19psi , rpms get higher , timing climbs to 20 degree's start getting a lil bit of knokc ( 5-8 counts ) timing tapers off a lil to 17 degree's, o2 drop to fuggin .76 and im just like wtf. i dont think my car is running lean, my plugs are really black actually, and theres a decent ammount of black smoke coming out my tail, from excess fuel i assume. I mean, it just really aggervates me that your supposed to be able to tune by it and that its supposed to be .88-.92 volts and mine is sitting here at .76 and its brand new. ( less than 2 months old. ) what do you guys think ? screw the o2 sensor ?? ( btw my egt's never got over 1550 )

 

[pballernh]

Narrowband o2 sensors are worthless, especially for tuning. All they are to the CPU is a little indicator of lean/rich. They get extremely inaccurate as they move away from stoich.

Wideband is the way to go.

 

[CanadianTSi]

Since you can see it, tune for no knock...

 

[EclipseOwner95]

Yah, thats what ive been doing, but i wasnt 100% positive on the fact taht lean = detonation / rich = no detonation, i didnt know if i could run lean and still not detonate.

 

[BOBS90TURBO]

Thats a good question, does anyone know.

 

[kpt4321]

I'm not sure what the question is supposed to mean. "Lean" is just a word that describes a general AFR. 15:1 is lean relative to stoich, but 10:1 is lean relevant to what the car might run on stock fuel maps. As such, I can't answer the question of if you can run lean and still not detonate. What do you mean by "lean"?

Have you pressure tested the car?

 

[EclipseOwner95]

Pressure tested? if thats a big word for boost leak check yes i have, and i dont have any. i mean lean as in my shits gonna melt .

 

[kpt4321]

Seriously, wtf. Your shit is going to melt? What does that even mean?