Car-2001 Honda S2000 80k

I replaced my motor not to long ago due to the previous owner blowing it, ever since i have had it back on the road the car will almost every day stutter or hesitate at low rpms and speeds only. My air fuel gauge pings out while this is happening. If i floor it it clears up and goes away and isn't affected unless i go back back down to a low speed and rpm. This doesn't happen everytime i drive the car but generally every day though. My car is mostly stock just exhaust has been added. My check engine light is on but only for a O2 sensor, any help would be appreciated thanks everyone.

 

Fix the o2 sensor problem, then see where you stand. O2 sensor problems can have symptoms similar to what you're describing, so take care of that first.

 

ok i will thanks

 

when you say "My air fuel gauge pings out while this is happening" is it reading really, REALLY rich or really lean?

 

Google "S2000 map whack"