Lean condition at idle

[MyNewSy005]

My Sy has started a slight stumble at idle. For the heck of it I hooked up a narrow band A/F gauge and I noticed when the stumble happens the A/F gauge goes full lean and the LED startes to fade, almost as if the signal is weakened.

Now is this becasue the O2 is going bad or is it becasue of something else which weakens the signal coming from the O2.

The A/F gauge is just a simple Auto Meter one that hooks to O2 sensor.

Any help appreicated

 

[bezerk]

Re: Lean condition at idle

datamaster or measure your volts at the O2 sensor.

 

[It's just a six]

Re: Lean condition at idle

What is your fuel pressure reading?
Narrow band is pretty much useless.
Only time it helped me is when my truck had a stock fuel pump & I could see it being full rich when I floored it,then shifted into second gear it would be full lean for a few seconds then go full rich,shift to third,then it would show full lean,then work it's way up to full rich & so-on.

Basically it told me my pump was not good enough.
Changed the pump & gained about 2-3 MPH in the 1/4.