Thank you very much for the answer!!!!... I'll be back with news about the results after review for a 'plugged cat', now I know what it is.

 

Hello everyone, I have a 2009 FORD F150 PLATNUM 5.4L (3v) 8V; I have replaced all coil plugs, including all spark plugs and one injector; I checked all cables, and they are working perfectly fine, and once I run it does the same weird noise and a little bit trembling, some mechanic friends recommend me to do the compression testing which I'm having trouble because I can't find the right adapter for my truck, I did my research, and supposedly my truck uses 12mm-1.25 male threads. I bought a compression test kit and used the 12mm; however, it does not fit; by any chance, does anyone know the right adapter for my truck?

 

If you have the fully threaded spark plugs, those are 12x1.25. The mid 2008 and earlier with the extended ground shield is 16x1.5.

 

We went to a mechanic for the reason that my truck 2009 FORD F150 PLATNUM 5.4L (3v) 8V is giving us the code p0303 (cylinder 3 - misfire) which we changed the coil, injector, and spark plugs; however, my truck continued doing the same thing. This mechanic told us the valve of cylinder 3 was bent and he had to rebuild all the engine and he was charging us $5,000, this is true? or what you can recommend to me? it confuses me it's only the code P0303 it doesn't mean the engine doesn't work at all, the engine works however its only haves that issue do you think its a minor problem? the reason I'm asking is that several mechanics are not honest they can charge $5,000 and do simple jobs to cars or trucks.