How do I fix the code p0171?

Question

Hi Reynaldo

I check the fuel pressure. With engine off and key in run position pressure is 50 psi. After that started the engine pressure drop to 31 psi. then with engine running I dusconnect vaccum hose from fuel pressure regulator no change in fuel pressure which is 31 psi. I make sure vaccum line has vaccum. When I try to give gas initial pressure drop by 2 or 3 psi and then went up.

What that means

Thanks in advance

Answer 1

The pressure at idle should be 48 to 51, KOEO,which is correct.  31 psi running is okay, Do a 10 minute test engine off test key off,sysle the key pressure will be 50 psi in 10 minutes pressure should be about 5 psi, if its less the reulator is suspected.