O2 Readings

[DaJoker]

I have a question about O2 readings on my Scanmaster. Gettting some knock on my SM as I rev thru 2nd gear. If I hit recall on my SM can I use the readings to tell if I'm too lean? Or do I have to make a full pass? I ask this because when I hit the recall button it shows high 600's, 698 to be exact. This happens as I go through 2nd and any detonation I get out of the throttle. Will try an get a 3rd gear reading once I get a brake tag on the car.

 

[TurboBuRick]

Sounds like a fueling issue. I would expect to see 800's in second.

Is fuel pressure keeping up with boost?

 

[DaJoker]

Don't have a fuel pressure gauge or an adjustable regulator. Its pretty much a stocker (gutted cat, 100# valve springs and a TT street chip). I have the AFPR and its next to go on. I was figuring I was lean. Also has a Walbro on it.

 

[turbows6]

I'd bump the fueling up 5% with the chip and see where it puts your 02's and see if it takes out the knock. As it's been mentioned, upper 700's should give you good power and some cushion for mistakes.