Continued check engine light

[Matrix6834]

Hello! So my truck has over 200,000 miles on it but less than 6,000 on the motor. However, when I drive I will occasionally feel a shaking vibration at lower RPMs and get a p0300 AND a p0151 code. If I hit about 70 mph it starts to flash at me. Then stops and is fine with the light on and drives more smoothly at a higher RPM. I have already replaced the wires and plugs and the o2 sensors multiple times. I’m lost. Any ideas?

[davester]

So, you put in a new crate motor 6k miles ago?

[silveradosid]

you have to find out what is triggering the p0151. could be an exhaust leak, bad wiring or corrosion in the plug. it could be that the 02 sensor has failed

[Matrix6834]

12 hours ago, davester said:

So, you put in a new crate motor 6k miles ago?

Yes. 

[Matrix6834]

5 hours ago, silveradosid said:

you have to find out what is triggering the p0151. could be an exhaust leak, bad wiring or corrosion in the plug. it could be that the 02 sensor has failed

I replaced the o2 sensors, plugs and wires I also replaced the exhaust system about a year ago. 

[silveradosid]

i mean the wires and plugs for the 02 sensors

[m reddington]

Could possible be a bad or intermittent crank position sensor . I had one on an impala and it was crazy.