I have a 1998 Expedition w/ a 4.6L. My check engine light has been coming on alot recently. I took it to autozone and they ran a test on it and it came back to be something wrong w/ the spark plugs or wires. I took it in..they replaced a wire and a plug and it appeared to do a little better but the light still comes on 30 mins after running and flashes the heavier i get into the throttle. I have cleaned the injectors w/ berrymans total system and it still rough idles and lags out when i get heavier on the gas. Any suggestions on what could be wrong?

try replacing ALL the plugs and wires and after that try a FULL tune up (ie: air filter, fuel filter, etc.) and if that dont work try the ignition coil.

Sometimes if your gas cap isn't placed correctly, it will cause that CE light to come on.

i will try all that..the gas cap isnt a issue..i fixed that 2 years ago.