Need Expert Help

[KWAD RCR]

So here's my problem. I have a 1998 Ranger XLT, 4.0, 2wd, automatic. I bought it with a check engine light. The codes were p0401, p0172,p0175, and p0735. The p0735 and p0401 was taken care of. I couldn't figure out the other two codes so I took it to a very reputable machanic. After two weeks, MAF sensor, another CPU, O2 sensors it still throws a check engine light, rich bank code. The fuel pressure was bleeding off so I brought it home and pulled the upper intake off so I could pull the fuel rail off and see if any of the injectors were leaking. None were leaking that I could see. This is where I need help. Anyone else have this problem?

 

[modelageek]

my guess is the fuel pressure regulator but i would check the air filter and make sure it is seating properly and nothing was blocking it.

 

[modelageek]

4.0 running rich

Did you put the truck back together and see if it thru the codes again. If you had a leak in the intake gasket you would have fixed it. You can spray carb cleaner around and if you have a leak the engine will rev. It seems that u have 2 issues. The codes being thrown and a leak in your fuel system. I am not sure if a bad gasket would thrown the rich fuel codes. But a bad FPR could cause both issues. Unfortunatly I think yours is in the tank. There is a procedure for testing it at the shrader valve but I don't know it.

 

[modelageek]

If you have the fuel rails still apart you should at least replace any orings on the rails and injectorts as well as clean them. I don't know what new injectors cost?