Low RPM/Throttle Hesitation

[Catnip]

The Z28 seems to have a hesitation under very low throttle at lower RPMs. I can let off the gas and press a little harder and it will skip the hesitation and just go. I replaced the plugs thinking they might be it, since it had a granatelli maf and was running a little rich (also has a brand new GM 3" maf as of today). Unfortunately, it still does the hesitation. At mid-WOT, it pulls hard with no miss or hesitation. SOMETIMES, it throws a CEL for an O2 sensor, but it's a random occurence... could this be causing it?

[jadakid88]

vacuum leak...

[Vteckidd]

yes the O2 sensor can cause it. 02 is only for mid to partial throttle aka gas mileage. It turns off (or ecu goes to closed loop) when you go WOT.

Change the O2 sensor

[Batlground]

The Z28 seems to have a hesitation under very low throttle at lower RPMs. I can let off the gas and press a little harder and it will skip the hesitation and just go. I replaced the plugs thinking they might be it, since it had a granatelli maf and was running a little rich (also has a brand new GM 3" maf as of today). Unfortunately, it still does the hesitation. At mid-WOT, it pulls hard with no miss or hesitation. SOMETIMES, it throws a CEL for an O2 sensor, but it's a random occurence... could this be causing it?

It could be the o2 sensor or a lot of other things. You can hook up a live scanner to it and view your o2 voltages and your fuel trims. Then you will be able to tell if its the o2 or the fuel trims. If its fuel trims consider getting it tuned.