Hey guys i have an 05 f150 5.4 triton and my engine light turns on when i accelerate really fast and i dont know what it is thanks

 

Time for a plug change and possibly COP replacement. A blinking CEL is a bad misfire. How many miles on the truck?

 

hey bxstang2000 Im at 79,800 kms. It first happend about 2 months ago then it started hesitating to start also there was a very loud clunking and banging noise coming from underneath the cab...maybe catalytic converter? and hasnt happend since,until today but at least no clunking noise.

 

Check engine light flashing means everytime the engine missfires it makes the light go off. Also, if its under acceleration that means its ignition missfire. IE proably Coil going bad, also if you havent, you make need to check the plugs too.

 

thanks guys. can i do this myself or should i take it to the dealer?

 

You could do it yourself. But you need to be aware of the 3-valve plug change problems. Read up on the problem involved with changing the plugs (2 piece design) and read the TSBs. You will save yourself a lot of money if you do it yourself - especially if you replace all the COPs. First thing would be scan the truck to see what codes are coming up. Might save you some trouble just to buy all 8 COPs on ebay and replace them all.