How do you diagnose the need for a CPI injector? I've done an injector balance test which shows the pintles as all puting out the same amount of fuel. Turn the key on, engine off, fuel pressure jumps to 65, then it quickly drops to about 59, then slowly(within a minute or 2) goes down to 51 where it sits. Doesn't start hard, or smoke on startup. But the seat of the pants dyno says its not making max power. Check Engine Light is on, there are 2 codes, P0173, and P0175. Bank 1 and Bank 2 Too Rich. Fuel Pressure Regulator was replaced a year ago to get through emissions back then(same codes). I need to figure this out because I just put a MAF on it and that was $180 of waste. I can't afford to buy a main injector right now and that seems to be what I need. Cheapest one I;ve found was a V6 one on Ebay for $200... I'm losing it and probably missing something big because of it. I am about broke and need to sell the truck, but I can't sell it with a check engine light.