Problem with 99 Nissan Altima

[neo_brown]

Recently, I have noticed when I drive on the highway and I press the gas pedal, the engine revs really loud and lags to speed up. It goes as high as 5000 rpm! It revs for a few seconds and then drops, at which point the car finally starts to pick up speed. This is a stock 1999 Nissan Altima (no mods).

Also, on local roads, I noticed a significant drop in performance between gear shifts. When I start moving the car from a complete stop, the engine revs really high, and I have to quickly shift to the next gear.

It has been driven for 160000 kms so far. I have never had any major maintanance issues with this vehicle. Just the regular oil changes, few tire changes and break pad changes.

Any idea what the problem might be? Suggestions?

thanks,neo brown