I run a Reedy 25.5T paired with a Castle Mamba Max Pro ESC in my Associated TC7. I only race on on-road asphalt/carpet tracks. When I'm not 3/4 throttle or above, it has these crazy cogging issues.

The main thing is at low speed. If I try to just drive slowly at 1/4 to 1/2 throttle without turning the wheels at all, the motor gets cranky. Sometimes it'll do just what I want it to do, but sometimes it'll not accelerate when I push the throttle a bit more, and sometimes the motor wont respond at all for a few seconds while I proceed to mash the throttle to try to get it to respond.

This all gets worse when I try to steer.

I don't know. If anybody could shed some insight or previous experiences with these motors, I'd sincerely appreciate it.

Have you tried recalibrating the esc?

If you haven't already, try a new known working sensor wire. A bad one can cause all sorts of weird motor/esc behavior.

It could also be a lack of BEC power. I remember quite a few people complaining about a weak BEC when using 6v or higher servos. It can be switched up to 7 volts but you'd need something to program it.

Since it gets worse when you try to steer, it may be a very quick/interment brownout and the cog is really a loss of signal rather than the traditional cogging effect - you may need a glitch buster. However, would try a new sensor cable as mentioned above first.