When i am in 1st gear or 2nd gear and at verry low rpms, when i give throttle my engine makes an extra abnormal sound that sounds like an extra gear or soemthing its herky jerky sound (somewhat like the sound sometimes heard in reverse.) It jsut started recently (all i have done recently i changed MTF). Im not sure how else to describe it but its a sound in addition to the regular engine revving sound and it happens only in lower rpms when u give throttle.
Could this be the knocking some people say they have when they use lower octane gas if someone could describe that sound maybe thats my problem?