I have a 1997 cvhevy cheyenne with a v6 and 94,000 miles. When driving down the road at any speed if I push the pedal to the floor the transmission down shifts and the rpm's go up to about 4,500 but the car's speed remains the same. Then if I back off the gas just a little it begins to speed up slowly. After doing that a couple times the check engine lite came on. I took it to auto zone and they pluged in a computer wich said that the input voltage on three of the oxygen sensors was too low. It also said that multiple random misfires have occurred. What could be the problem and can I fix it myself? The numbers the computer gave was 131,137,151 and 300.