iridevmx

I have been dealing with this issue for awhile now and average 13mpg. codes are: rpm signal, #1 & 2 knock sensors and a/f.... heres what the car does, i can cold start it and drive it until it warms up and there is NO hesitation until it heats up. also every time i restart the car the light goes alway until my car shifts into 2gear while warm UNLESS i stay under 2000 rpm. i really dont want to replace the knock sensor and that not be the problem. HELP ME!!!!!