Hi, I have a 2005 Ford Focus SES Zx4 with 103,000 miles on it. I bought it with 98,000 miles and had it checked out and everthing seemed good. However lately I noticed that my acceleration has been inconsistent; sometimes it is really good while other times even if I almost floor it the rpm either barely goes up or I get the acceleration of something like a minivan. Overall though it's automatic and changes gears fairly smooth and the engine sounds pretty good.
I was hoping to get your opinion on fuel injector cleaners and intake manifold cleaners. Do they work for a car of this mileage? I was thinking maybe built up carbon may be causing a loss of acceration but would the cleaners be strong enough to clean carbon that's been on there for a long time?
Lastly, what is your opinion on spraying a product like Sea Foam into the Air Intake manifold? I see videos of lots of smoke coming out of the exhuast, supposedly being carbon deposits, but I'm not sure what the real experts think about it.
Thanks for the help! Any other maintence tips would help.