03 Focus cuts out during acceleration

Recently bought this vehicle. It would start and idel just fine. But as soon as you were accelerating down the rode it would start to cut out. First I replaced the fuel filter - no improvement. Second I went for the plugs and wires - no improvement. Next was the air filter - ah huh ! The first sign was the air box bolts were rusted so bad I couldnt get them out. That told me it had been a long time since someone replaced the filter. Sure enough. I put in the new air filter, cleaned out the air box and problem solved.

Thanks for sharing that with us. Your gas mileage must have been terrible. Hopefully you will help someone with a similar problem. THANKS!

wow, for bolts under the hood of a 2003 to be rusted to the point of not being able to remove them suggests someone lost the originals and threw in some old bolts laying around. or they used bolts that were not designed for the elements. still though, by that time, you could say for sure it had been neglected. good work!

You need plenty of air, fuel, and exhaust for acceleration, have your catalytic converters check out.