I have a 2001 Ford Focus 2.0 L 16 valve DOHC-The problem started when my daughter had the car and she ran out of gas what happens is when driving from a stop car seems to be fine but as the RPM's climb and press harder on the pedal the car faulters/stumbles, in which it will not accelerate, making me back off of the pedal to slowly(very slowly) accerate. So far I've Have replced the fuel filter, spark plugs ,wires and coil pack also had a new throttle body put in. The Throttle body was put in before she ran out of gas.All the other parts were done after wards So I am looking for some suggetions on what else it may be.

it could be the fuel injectors. sometimes running out of fuel can damage the injectors. you can find out by doing a power balance test to look for the bad injector

running out of gas is harmful to one thing, INJECTORS!!!!!!!!!!, injectors pulsate at what 1000's of times a minute, when you accelerate you increase that, but believe it or not, the fuel passing through keeps them from over heating, you run out of gas, they pump hot fumes, burns them out...it's ok to blame your daughter on this one....we will let that go...(joking), as i reread, plugs and wires are always nice to replace, not so expensive there, the fuel filter good idea as crap can be clogging it...so when you see the price of the injectors, be sitting down....and know valuable lessons were learned by all. anything else drop me a message

I have a 2001 Ford focus and it only drugs when I'm out of stop and I'm almost positive it's my fuel filters any of you would now please answer me thank you