the bank one 02 is reading weird. when I start up it runs 1.125 or as low as .875 then as it warms up it switches between .225 and .750 obviously not eactly on those numbers but a range thats close.. after I drive for a while for 15 minutes it eventually goes down to .50 on the low and .150 on the high..
if I turn the car off and let it sit for a few minutes, the whole process starts over o2 reads fine. I've noticed it doesn't change with the warming of the engine though. Sometimes it reads wrong right off the bat and sometimes I can drive all day.. do you think I have a short. this one is on the side I had the coolant leak from the heads. is the 02 just messed up from the burnt coolant?

 

I would first - put that live engine scanner on another car and see if it scans the same way.

Also if bank #2 is normal - up to .9 and down to almost 0 then you are set.

Those readings on bank #1 which is driver's side indicate you need to get a new Bosch O2 sensor from Amazon.com

Upstream - or the one closest to the engine.

 

I use my ultra gauge on all three discos (my two, and my brothers). I am confident in its accuracy. and yeah it appears to only be that one 02(upstream drivers side). I was just concerned that it didn't start until about 100 miles after the head gasket change. but the engine is running considerably better than it ever has. and there isn't coolant on thet half of the y pipe anymore now either. and I did notice it never exactly agreed with the more consistent bank two unit. it has always ran very "smooth". but now it runs smooth and has great power. so I don't think I have any kind of vacuum leak. just wanted to make sure anyone didn't have any ideas before I go to advanced auto and get an 02. it doesn't seem to be reading false consistently so I think it may just be toast.. just wanted to run it by you guys.

 

wow amazon IS way cheaper

 

At your mileage, if you haven't replaced your front 02's, I would start there and make sure you clean any and all grease/oil from the connections with electrical contact cleaner then add some die electric.

 

Rock Auto is actually cheaper then Amazon.
If you replace the fronts, why would you not replace the rears at the same time?

 

because I just spent a grand on the motor and some other stuff and you haven't offered to buy me all four yet!