Have had the same throttle control "limp home" problem cited by many 2003/2004

Are any codes present? IF so post the codes and we will try to help!!

run your VIN# to see if any recalls to related failure. throttle may need to be cleaned. review when last tuned. rec. premium type spark plugs(e3) as replacement. if you have to replace coils then rec. performance grade. accel supercoils are good and are more cost effective than OEM replacement. rec. upgrade from conventional air filter to high air flow design(K&N). rec. fuel system clean. ethanol treatment to 1 tank of premium. ethanol blend in fuel causes build up in fuel system, combustion chambers, exhaust and causes increased wear to spark plugs. it may cause your sensors to trip. rec. oil stabilizer treatment with next oil change. this will recondition seals and cylinders(improve compression).