Running lean? Opinions welcome

Well as seen in my dyno thread. At WOT around my 4000rpm my Camaro will lean out to almost 14.0 . | LT1 M6 with mods in sig;

Currently i am throwing a code for the drivers side o2 sensor. However i believe this is because of my headers and the sensors being further down stream now. Im going to be wrapping both of them soon in an attempt to get rid of the code.


Another thing is that these o2 sensors are the same ones that have been in the car even before my coated header install, could the coating have ruined them in some way to cause them to lean the car out like this?

Another thing im wondering is if maybe its the tune? Im sort of doubting this, but i dont know what else would cause the afr to run lean and be so consistent about it.(not jumping all over the place).

The maf sensor didnt look all that clean either so, i imagine ill be cleaning that soon also.

anyways, opinions welcome. As said, im doing h/c swap in the spring and will for sure be getting a dyno tune with it then, but i figured id ask now seeing as i have a couple weeks left before the evil snow falls. Thanks

How many miles on the O2s so far? Did they look totally black when you pulled them out?

You'll probably want to think about replacing the O2's from what I've seen. The initial burn off on a fresh set of headers has been known to kill O2's. If anything get a real time scanner on the car and see how the O2's are switching.

Oh god.... Uh, ive probably put a good 1000-1400km on these o2 sensors since the headerinstall.

They were fairly clean looking when i pulled them out of the old manifolds. I had them out about 2 weeks ago when i tried to install ngk sensors and they still looked pretty healthy per say.

EDIT:. THats what i assumed i was going to have to do. Ive just figured id get a few other opinions before i go and spend almost $200 on factory o2 sensors heh..

Yep, if they dident look too bad when you pulled them out then chances are a little of the coating burned off on the inside and got em'.