question about a/f ratio

when i let go of the gas while im in any gear and let the car rev down is it suppose to lean out>?

does it start sweeping back and forth within 4-6 seconds after decelerating? if it does…it’s completely normal. if it stays lean, you might have a problem.

also, are u running a wide band or narrow band air/fuel ratio gauge? reason i ask is because the wide band is a lot more accurate, and the narrow band is pretty much just for show.

It’s called fuel cut. Yes, it’s normal for the car to do this WHILE decelerating at no load (normally less than 5% throttle), over 1800 or so RPM, but it should recover from fuel cut within a second or so of pushing back on the accelerator, or going below its low RPM threshold. If when you get back into the accelerator it stays lean, or stays lean even below 1800 rpm while it’s not even decelerating, then no… It’s not normal.

its stays lean … i have a wideband , and i noticed it on the highway wen i left of i havent done it on the streets ill check it if recovers, but i know for a fact on the highway when i let off its around 3000-3500rpms and it stays lean and does not recover

So when you push the gas pedal after a decel, it stays lean? How long are we talking about?