Nissan Repair: 1995 Maxima fuel injectors, oxygen sensor, lean condition

Question
About a year ago our Maxima was missing quite a bit and we had a mechanic change the 3 back injectors under the manifold.  Car has run well til recently when it has started erratic missing again.   I am quite sure there is a bad injector.  The front ones are original I believe, with 254000 miles.  I put an ohm meter on them and all three show 28-30 ohms resistance.  Do you think they are bad?   Thanks, Richard   PS   The check engine light is often on and codes show oxygen sensor is bad.  Could this come into play here also?

Answer
Richard,

The injectors can ohm out ok but still be defective.  I would check the fuel pressure to see that it is within range and make sure they do not leak down after you turn the key off.  An oxygen sensor will make the car run rich with the age of yours.  The code is probably showing a lean condition due to the sensor being coated.  I would replace the sensor and check the fuel pressure.  Email me back with what you find.