i have a 2008 chevy tahoe flex 5.3 keep getting p0300 and p0174, after engine
replacement and possibly codes were thrown prior to replacement
JA: Just to clarify, what's the exact code? And have you tried to reset it?
Customer: p0300 and p0174
JA: Are you fixing your Tahoe yourself? What have you tried so far?
Customer: i am, and i have replaced the 2 front oxygen sensors, maf sensor, spark plugs
when swapping motor, crankshaft sensor, (relearned with scan tool), with the scan tool i monitored the cylinders and getting 1,3,2,6,8 missing but keeps setting p0300
JA: Anything else you want the mechanic to know before I connect you?
Customer: i tried swapping coils around, injectors i also checked fuel pressure running i have 48psi, with key on i was getting 55psi, now when i cycle the key there is no psi i also dont hear the pump cycle until i start the vehicle. then the psi goes up to 68psi when i shut the car off, but during running its48-50 psi, and its a flex fuel tahoe, thanks