02 Dakota 4.7

I have a problem with my 2002 Dodge Dakota 4.7. I keep getting P0172 rich on bank one code. I also have missfire on cylinders one and eight. My fuel trims are -30 to -33. I can not find any vaccuum leaks. Upstream and downstream O2's have been replaced. TPS, IAC, coolant temp sensor, and cam sensor have been replaced. The milk is fine seems to get worse the as the engine gets up to operating temp and around the 45 to 55 mph range. The miss will intermittently cause the truck to jerk. My spark plugs on cylinders one and eight are black and chalky. All the other plugs are white and chalky. I have been chasing this problem for about 2 1/2 months now and can not figure this out. Can someone please help me before I completely loose my mind?

"My spark plugs on cylinders one and eight are black and chalky"
Leaky fuel injectors?

I’d suspect injectors. Do you have a fuel pressure gauge? Those should be easy to check pressure on if I remember they have a schrader valve on the fuel rail check and see if pressure bleeds off

Pressure bleeds off over 10-15 min. Is this normal or should it continue to hold pressure.

Not sure bu I will get it checked

How much does it bleed down in that time frame??

Cheryl, yes it does have the Schrader valve. How long should it hold continues pressure. It seems to drop a little after 10-15 min.

About 8-12 psi

I’d suspect leaking injectors

Ok. I will pick a couple up at the parts store. Would you recommend getting all eight or just replace the ones in the two cylinders that have the missfire?