Power some times then a little less others

[jhonda]

Like the title said Some times it runs like a bat outofhell for being pretty much stock (catback and timing) and others it seems a little sluggish....not bad but you can tell a difference....I know it has all the orginal equipment on it but I did a tune up when I first got it about a month ago (plugs wires rotor cap and button) and I it helped a little with idle and gas mileage 22mpg. I know it has the stock O2 sensors in it could it be those? any suggestions
Thanks
Jason

 

[88mouse]

How many miles are on it?Did you change the fuel filter?

 

[jhonda]

Yea got a new fuel filter on it also. It has 78000 miles on it now

 

[88mouse]

It maybe the type of gas you are running.My car loves shell,but hates exxon.

 

[jhonda]

well I always run 93 but It does it at least once a day....could it be the Maf sensor, or O2 sensors. I had a couple of codes # 96, 13, 31