ok well i started my truck up on a cold start heard a rattleing coming from undeneith then continued to drive it it wont through a code untill 70 mph then it blinks and if i slow down it goes away. When im at a stop light the truck bogs down then the rmp gose down then up and the truck shakes ive never done anything with the egr so im thinkin something is messed up there any ideers guys thanks

2003 f150 supercrew 4.6 160,000 miles

 

A flashing Cel means a misfire. when was the last tune up?

 

not even 10,000 miles and a flashing light i thought was a hard code

 

U should check the Trouble Codes!, flashing cel is meant to get the attention of the driver because there is a serous problem.

 

Not sure what you mean by "hard code" but it means misfire.

First thing to do is check the COPs (Coil on plugs), because that is a very likely culprit. Get the code(s) read, and it will tell you which one to check first.

 

there is no cel until you get to 70 but now there is no boging or anything its like it fixed its self