Help with ECU codes 14, 34, 105

[anthony_S14]

1995 240sx SE manual transmission:

Realized that my check engine light had not been coming on and got around to checking the bulb that illuminates it. Turns out the bulb was out but now my ECU is throwing ECU codes 14 (Vehicle Speed Sensor), 34 (Knock Sensor) and 105 (EGRC Solenoid/V). I wanted to take care of the most simple fix which I thought was the speed sensor. After placing the car on jackstands and pulling the speed sensor from the transmission I was wonder if it could be something other than the speed sensor because the speedometer works fine. Would the other 2 ECU codes cause the speed sensor code to show up? I really would hate to waste some money on a brand new speed sensor only to find out that the code is still showing up. By the way, I cleared the codes and drive around for about 3 days and all three codes showed up again! Can someone give me some direction? Thanks guys

[anthony_S14]

anyone?