You Wrote"My check engine light comes on an hour or so after resettting the computer. I get code P0170- fuel trim malfunction. I have cleaned the MAF sensor, new oxygen sensors, new plugs and air filter, and cleaned the throttle body. Any ideas on this??? Thanks, fred fisher"

Fuel trim errors are mostly caused by the O2 sensors reading a lean condition. Lean, meaning "not enough fuel". If the Fuel Filter is plugged up you will "not get enough fuel". If your Fuel Injectors have excessive varnish built up on them you will "not get enough fuel", If your Fuel Pressure is not correct, you will "not get enough fuel". Do you see where this is going ?

In your list of items replaced, I don't see Fuel Filter.

If it was my car, I'd check the Fuel Pressure to rule out pump or regulator, analyze the fuel trim adaptation numbers, then based upon the findings, I'd procede from there.

If I didn't have the pressure gauge for the fuel system pressure test, I would replace the fuel filter and run some high quality fuel injector cleaner like Red Line through a tank full of "good" gas. Reset the light and see how you go.

Let us know what you end up doing.