My old O2, when I pulled it out, had a coating of carbon on it just like the rest of the exhaust system. Now I'm changing it again, and the last one I put in has a greyish-whitish color to it. I take it my exhaust is now lean, even with 23# injectors and stock FPR? Or is this something worse? Thanks guys.

------------------
1990 IROC 350
Mods: Too busy trying to make it run right to mod it.
Airfoil, Dynomax cat-back, MSD coil, 180 t-stat, Bald Eagle tires,
Hypertech fan switch, Accel 23# injectors, Holley module, ported plenum,
Ported Daytona Yellow stock base, Moroso valve covers, other stuff,
Streetdampr, Ruger P95DC, hot wife, new oil filter, !cats, !TBC, !AIR.
18.0 @ 85MPH since I'm one big-a$$ MF
"It's better to have and not need than to need and not have."

 

Jethro,

I've had them come out anywhere between an almost a silvery-white (like a lean exhaust), to a medium/light tan, to a dark brown/tan color. I've read good signals from all of them, but the gray/white color seems to be most common in a properly running system. Excessive carbon buildup may insulate the sensor and skew the readings, but I would think it would tend to drop the signal to an unusable level and keep the ECM in open-loop (extra rich) constantly.

------------------
Later,
Vader
------------------
"Click - Click - BOOM!"
Adobe Acrobat Reader