oxygen sensors

[Greg Woods]

OK for those of you keeping score with my GM TBI swap into
an 86 2.8l cherokee, here's some recent updates...

Thanks to all who recommended replacing the TPS for my 
last problem.  That was right on the money.  I placed
a new TPS in my throttlebody, rotated it for 800mV at
idle and the "Low TPS voltage" error code disappeared
as did my High idle problems (which makes perfect sense).

The latest error to be strobed from my 86 GM ECM is
an error 45, which is an "O2 sensor indicates rich exhaust"
code.  The vehicle is still missing at low RPM's on
acceleration, and I'm experiencing engine surges/hesitation.
The O2 sensor is brand new with less than 2k miles
on it.  However, it was a cheapy sensor that I bought at
Autozone for $18.  Should I replace the sensor with a 
higher dollar/higher quality model?   Would anyone like 
to recommend an O2 sensor for this?  Is it normal for
cheap O2 sensors to fail prematurely?

any and all responses welcome!  (I'm still new at this
FI thing, but even with these problems, my FI system
still works better than my old carb!)

greg woods
gwoods at symtx.com
austin, tx
86 XJ, GM TBI