help help help blinking check engine light

[vj72ct]

well when i punched the cats i tried the oil foulers on the 02 i dont no if they are working but i dont think thats causing the problem.as far as throwing money at it.the codes pointed to the sensors on the top of the fuel pump module so i figured instead of changing the sensors ill just buy a pump cause the truck has over 300k on it and i have no idea whats ever been replaced.i think the scan tools will show me fuel pressure wont they?havent changed or checked the pressure regulator.ive got a 2005 sierra 2500 6.0l in my garage lq4 motor that im building for my swap do they use the same regulator if i need to ill steal it off that motor.the problems driving me nuts cause im nervous about doing my wap caue im afraid these gremlins will carry over to the new install.if i have the codes shut off thru the tune will that affect the way my truck runs or does my custom tune overrides that?

[blacstar]

well when i punched the cats i tried the oil foulers on the 02 i dont no if they are working but i dont think thats causing the problem.as far as throwing money at it.the codes pointed to the sensors on the top of the fuel pump module so i figured instead of changing the sensors ill just buy a pump cause the truck has over 300k on it and i have no idea whats ever been replaced.i think the scan tools will show me fuel pressure wont they?havent changed or checked the pressure regulator.ive got a 2005 sierra 2500 6.0l in my garage lq4 motor that im building for my swap do they use the same regulator if i need to ill steal it off that motor.the problems driving me nuts cause im nervous about doing my wap caue im afraid these gremlins will carry over to the new install.if i have the codes shut off thru the tune will that affect the way my truck runs or does my custom tune overrides that?

get a fuel pressure guage and check it. putting parts on based on the dtc's you have is not fixing the truck the right way. a bad regulator can cause the o2 codes, fuel sensor codes, and so on. im not saying thats ur fix.... all im saying is you need to properly diagnosis the truck. start with the basics on what an gas engine needs to run; air, fuel, spark, and compression. go thru each and make sure they are correct. damn now im typing too much!