I have a 99 f150 5.4 4wd that will not start. Was driving it and started jerking and threw a bad code. P0340 i believe and so i changed the camshaft position sensor but still will not crank. My mechanic said it probably will need a new engine because he has checked it but he can't get it crank either.
Before buying an engine get a breaker bar and a socket set. Attach the socket wrench to the serpentine belt on the drive pulley . Take out of one the spark plugs and see if you can turn the motor over by hand. If you can get it to turn listen to see if there is any scraping going on inside the motor. Make sure to do that before buying a new motor because if it isn't locked up it should turn over. With the cold weather I would honestly test the battery first. A bad battery might work during warmer weather but once it gets cold they quit in matter of several times of turning the vehicle on.
@Haase242 can you copy and paste your answer below under the box “Your Answer”? That’s where it belongs. Thank you.
Start with replacing both 02 sensors. Next, try a bottle of catalytic converter cleaner. Clear the code and drive it a little while and let the ECU reset. Or try the cleaner first, then the 02 sensors. It may just fix it.
