Hi gang, a newbie here.
My problem is with 'da wifes car, drove it last nite and noticed at hwy speeds 55-70 that when you are taching steady that the engine seems to rapidly cut out or surge, although it happens so rapidly it does not show on the tach.
Has any one else had or solved this problem.

It goes away if you accelerate or put the car under a load but it is a minor annoyance.
Car has 187,000 miles, has had the fuel rail recall done and always well maintained , however i am ashamed to say has the original O2 sensor.
Any ideas or suggestions appreciated

 

try replacing the o2 sensor and cleaning the throttle body. Then run some injector cleaner with a new fuel filter (part # FF651 at autozone or you can get one from a 90-96 300zx).