07 impala 3.9 lifters
 

I have a impala 3.9 when I go over 3000 rpms I get a rattle and the engine light flashes get an p0300 code.my shop said it was the lifters and the only way to fix it is to replace the lifters and cam and do the block off.he quoted a price of 2100 dollars. has anybody done this before and how hard would it be. engine have to come out or is it possible to leave it in?

ANY body here??

PO-300 is a Random Mis-Fire Code. Unless there is a well known issue with lifters and setting of this code, I do not see the direct connection. This code could be set by many different issues, from a bad coil pack to wires to any number of things. I had this code come up on my old S-10 Truck when the throttle position sensor was having issues. I would defiantly seek another shop if they can not provide a good explanation of how a random mis-fire code directly equates to bad lifters and cam.

so far I have replace the spark plugs,plug wires, coil pack tested the fuel pressure at 60 psi,check the catalytic converter.it does have a rattle around 3000 rpms and thus 3.9 liter Active Fuel Management are known for bad lifters from what I understand.