Over time, our 95 Pathfinder has been losing power. When accelerating it kind of wants to bog outand you really have to press the gas pedal into it. Also, on the highway, it will bog or lose power and you find yourself pushing into it with the gas pedal more and more to keep it up to speed. There are no check engine lights. It kind of feels like the brakes are being applied. It doesn't miss or die. It sounds okay, it is just losing power. Is this indicative of an O2 sensor going bad? Another theory I have is maybe the ignition module or coil is going bad resulting in a weak spark. I have purchased a new air filter, but haven't put it in yet. Will tonight. Another thought I have is that there may be some problem with the throttle body. Just not sure. The transmission is always shifting down to get it back up to speed. It seems underpowered or something.

Also, it seems to REALLY be getting bad gas mileage. Worse than before. It never has been real fuel efficient. Yesterday, it really sucked the gas. I went about 70 miles and it used around 6 gallons of gas. Fortunately, this is a spare vehicle. It used to get around 16 MPG or a little better. Seems like about 10 MPG or a little better now.

Any ideas are appreciated!

I had the same problem with my 95' PF SE. I took it in to a trusted dealer and it was the mixture of oil and gas was bogging my gas milage to 10mpg. I guess the Mixtures were too rich. They also said something about a wire that was not grounded underneath my passenger side seat that was causing my car to bog out. Hope this helps!

p.s. it cost me like $110.

Thanks for the ideas. I think it may have been my air filter! It was extremely dirty and clogged. So, like you said, it was running to rich because it couldn't get enough air. I changed the filter and drove it a little ways. It seemed to run pretty good. I will look under the seat for that wire. It is amazing what a faulty ground wire can do to a vehicle.