i was looking over my first scan ever and now i have some questions. the first part of the scan was done at idle with the engine up to temp and in close loop.

its my understanding that above 128 you are lean. for the BLM

my readings are in the 150-156 range at idle. that says to me that i am lean. right?

my O2 voltage seem to be all over the place. flipping from min to max very quickly.

i took the time to pull the plugs and they all (every one) looked very rich. the plugs were in the car for less than 3000 miles and were black.

my questions is this

1.should the O2 flip from min to max in less than a second as the scan shows? and if not what should i be seeing

2. why would the BLM show lean and the plugs show rich?

 

1. the O2 sensor should flip between lean/rich yes....
2. Change O2 sensor, I also had strange BLM values when I started to scan and tune- replaced the O2 sensor and It became much easier....

/N.

 

Definately get a new O2 sensor.
I was in the 140 BLM range when I first started my new eng.
Replaced the O2 sensor and my 140s changed to 108s.
My original O2 sensor had moderately high cross counts too.
Eng went into closed loop a lot faster after replacement.

 

that is with a new O2.... well new with the plugs and only 4 months old.

think i might just try a new one anyways to see what i get

 

People speak of having to use O2 sensor safe sealants to prevent premature death of the O2 sensor.
Personally, I've yet to figure out where the "dangerous" sealants can be used and where they can't.

Only place one would normally use sealant is on the cooling system (I.E. water pump seal, thermostat housing, etc.) and under the intake manifold at the ends. Can't see how that could effect the O2 sensor. Anyway, just a thought.

 

Do you mean on the O2 sensor threads??? I never use anything except a little dab of Type-13 anti-sieze compound. I'm pretty sure it's safe for the O2... it may even say it right on the tube.