Hello I'm considering buying a 2004 6.0 that needs some work, it has head studs and and egr cooler delete on it already, but it doesn't start the best cold and has ok power, but it takes like 5 seconds of pushing the pedal to feel any sort of decent response, it has 4 codes on it currently and will be doing a cylinder contribution test and buzz test tomorrow with my scanner, but here are the codes
P2290
P0281
P0279
P0275

Im fine with putting new injectors in it but I'm looking and seeing that it could be and ficm, or a few other things, I'm wondering what your input is and what you think it could possibly be?

 

P2290 on a 2003 or early 04 6.0L is most likely cause by (in order of likelihood):
1- Failing, cracked and leaking ICP sensor and oil damaged wiring at the sensor
2- A weak or failing High Pressure Oil Pump
3- IPR valve
P0281 - Did you do your contribution test while cold to see if where the issue is? Did you disable power balance? Have you checked your cac tubes for oil? If it's all still good then I'd say compression test the truck make sure that's okay if all checks out. If everything else is good I'd say either failed copper washer or leaky / failing spool valve?
P0279 - Most common occurrence is the wiring has rubbed up against something and now instead of sending the firing voltage to your injector, it shorts out to the chassis. It could also be that your wiring has come loose, but that is a less likely scenario since it is only occurring on one injector. Keep looking because the chafed wiring is sometimes difficult to find. Follow your FICM connections all the way to #7 injector.
P0275 - see 0279 above

I would suspect injector harness and possibly HPO system leaks. Could be a lot of things. I would do a complete oil change and run it a few hundred miles and then do it again. Check the injector harness. Test the HPO system for leaks. HPO system problems could very well be causing all of it, or you could have multiple problems. Pull live data and see what the ICP and IRP readings are. If you have the ability to do a contribution test, do that as well. Buzz testing the injectors and doing a resistance test on the injector coils may also be a good idea. Inspect you injector wiring for shorts or chafing. If you can do the work yourself you may get out cheap by replacing the HPO rail nipple cups and seals, replacing all injector seals (AP0002), and disassembling and cleaning your spool valves. Or, you may have to replace the HPOP and possibly ICP and/or IPR. If your doing the work yourself it may not be too bad. I guess worse case would be new HPOP, IPR, ICP, injectors, injector wiring, and either reseal and replace nipple cups or replace HPO rails. I guess it all depends how much diagnosing you can do before buying or how cheap the truck is.
Keep in mind, I'm no expert on these engines. I'm new with this specific engine, but I know the HEUI system on the C7 very well and have been researching the 6.0 a lot since I got this truck.