well guys my uncle bought a 97 powerstroke. ionly upgrade is a 3 inch striaght pipe. it ran fine to begin. now it has a bad miss to it. he brought it over and i checked it for codes. the codes are:
PO236-Turbo Boost Sensor A Circuit performance
PO470-Exhaust Back Pressure Sensor Circuit Malfuntion
PO478-Exhaust Pressure Control Valve High
i cleared the codes and the second two codes showed back up right away. i found a wire unhooked so i pluged it back in. i think that was the first code since it was by the turbo.

 

I would say those two are a result of the straight pipe since will make all your back pressure go away so its no harm unless those are making it miss then i dont know what to tell ya maybe get a performance muffler and stick on it see if that helps

 

straight pipe is fine. might have a injector going out.

 

Any luck on this one?

 

i told him that it might be an injector. he said he'll look into it.

 

Check your oil level.

Next, start checking the pigtai connections on the Valve cover gaskets. They tend to melt and lose connection. Very common. You can physically see it if you pull the valve covers and the gasket.

After that you need a Bi Directional scan tool to run the tests on the injectors to see if you can locate anything.

 

Did you find a resolution?

 

i told him it was probably an injector problem, but he dont have he money to fix it right now

 

I see. Any problem with closing this thread for now? You can always reopen it later if ya need too.

 

Ed im closing this for now, you can re-open it back up if you choose.