Nissan Repair: Service Engine light and trouble codes, nissan 240sx, eric barnes

Question
I have a 1995 Nissan 240sx.  Recently the check engine light came on, and I took it to Advance Auto to have the trouble code read.  It revealed that it was the knock sensor, so I replaced the knock sensor.  Two days later, the light came back on, and it revealed that I had an Oxygen sensor malfunction, so I replaced both of them.  The light then came on again, and it revealed another code, about a Pressure differential sensor malfunction.

My question is, if that is a problem, can I still drive the car, until I get it fixed, because I have to drive it home soon which is 700 miles.  

Secondly, is there another cause for making the light come on, and have various error codes, or is it possible that all of these sensors malfunction at once.

Thanks

Eric Barnes

Answer
Eric,

I do not see that many sensors failing all at once.  I would unplug the computer from the harness and reconnect it to see if you have a loose pin or two.  Be careful not to bend the pins.  There is a lever arm that has to be lifted to get the connector loose and then reconnect it.  Be sure to have the battery disconnected first and then unplug and reconnect the harness.  Now, reconnect the battery and the codes should be gone.  Hopefully they will stay gone.  I have seen this trick work several times.  But, I have seen where the harness was damaged in the firewall area and have to be replaced.  So, give it a try.  And, if you want to wait the car will run until you get those 700 miles behind you.  The car will run in limp mode so you should make it home without damage to the car.