Volvo Repair: Engine Light, needle nose pliers, v70 glt

Question
I took the car to a Auto Zone and they read the code as "Lean".  I belive it was P700 or P1700 something.  I could not see the code reader very well.  This is a '98 V70 GLT.  Low pressure turbo, 98,000 miles.
I am putting in fuel injector cleaner in case there is a dirty F.I. nozzle.  I will have to check the plugs also.  However in reading up, it seems the oxygen sensor may be shot.  
Will the engine lite reset itself if the F.I. cleaner does the trick?  
If its not the F.I. system can the sensors be cleaned or do they need replacement?
Any thoughts appreciated.
Eric  

Answer
Hello Eric,  Two things,one Volvo engines hate a vacuum leak.there is a small 'elbow'hose to the pass.sd,of the intake manifold,its known to leak.Repace it if bad.Its a tight fit, try it yourself ,cold engine nicer to work on.I drain the coolant so as to move the upper coolant hose out of the way,Then use a carpet knife to remove the rest of it ,it WILL NOT JUST PULL OFF.Using two long needle nose pliers. Hold the plastic tube with one and install the new 'elbow' with the other. If this is too much see the shop you use,a pro can do it in about 45 min /1hr.Second the code may go away but it could take months.Replacement is best,they are considered a 'wear items' and your car has a front and a rear o2 sensor.Thank You and good hunting!  PKD