po300 cant find the problem

Question

Po300 99 chevy tahoe. New engine that ran fine. The original motor had the same code brand new wires plugs. Whats causing this problem

Answer 1

P0300 Random misfire

There is a variety of reason for a P0300, A partial plugged exhuast system such as a plugged catalytic convertor can cause a P0300, The intake manifold gasket taking in vacuum leaks. , or even a low compression of a cylinder.

 Sparkplug condition should be checked, here is  fouled sparkplug form a Chevy suburban , which help determine that the fuel pressure regulator was leaking fuel into the intake through its ruptured vacuum port.

 Here is a Chevy where the catalytic convertor  or plugged exhaust was suspected of being the cause for a P0300, The exhaust bolts that attaches to the exhaust manifold where loosely connected, and tested for a random misifre P0300.  at idle . the cause was plugged catalytic convertor.