P0171 Error Code
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P0171 Error Code
Sorry if this has been answered elsewhere. I tried searching and couldn't find anything.
I have a 2006 Ford Ranger with the 3.0L v6. The check engine light came on and the code it is blowing is a P0171. It runs rough at idle or when I let off the accelerator and "fine" at speed.
The code told me to check/clean the MAF which I have done. Next on the list that I saw was the PCV valve. I disconnected the electrical to it and then disconnected the hose. Some oil poured out of it... not a lot but some... The valve still seems free, it clicks when I rotate/shake it and I can blow through it (I know, highly scientific). I can replace this (if I can find it, Napa and Advanced Auto don't have a part that looks like it...) but I'm wondering what else could be wrong. Any help would be appreciated.
I have a 2006 Ford Ranger with the 3.0L v6. The check engine light came on and the code it is blowing is a P0171. It runs rough at idle or when I let off the accelerator and "fine" at speed.
The code told me to check/clean the MAF which I have done. Next on the list that I saw was the PCV valve. I disconnected the electrical to it and then disconnected the hose. Some oil poured out of it... not a lot but some... The valve still seems free, it clicks when I rotate/shake it and I can blow through it (I know, highly scientific). I can replace this (if I can find it, Napa and Advanced Auto don't have a part that looks like it...) but I'm wondering what else could be wrong. Any help would be appreciated.
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Joined: Jan 2004
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From: SW Va
Welcome to FTE.
I read P0171 as system too lean cyl bank 1. So look to something that could cause a lean code for just cyl bank 1, like an intake manifold leak, acting out fuel injector giving a lean squirt, lazy switching O2 sensor, ect.
If you have or can come by a scantool that'll read & display PID's, have a look at cyl bank 1 fuel trim & bank 1 O2 sensor switching speed & range. Use or rig a stethoscope & have a listen to all bank 1 fuel injectors to determine if one sounds different than the others.
If you come to suspect an intake manifold vacuum leak, rig a propane sniffer using an unlit propane torch, with a length of tubing attached & a sports needle on the other end as a probe & pass it along the bank one intake manifold gasket while listening for a change inidle speed or quality, or watch the scantool bank 1 fuel trim numbers for a sign of when it gets a whiff of propane, as the fuel trim should go richer. Propane is O2 sensor safe. EDIT: If you get a positive on the intake manifold leak test, maybe try re-torquing the manifold fasteners to spec in the proper sequence.
Some more trouble shooting thoughts for consideration, let us know how it goes.
I read P0171 as system too lean cyl bank 1. So look to something that could cause a lean code for just cyl bank 1, like an intake manifold leak, acting out fuel injector giving a lean squirt, lazy switching O2 sensor, ect.
If you have or can come by a scantool that'll read & display PID's, have a look at cyl bank 1 fuel trim & bank 1 O2 sensor switching speed & range. Use or rig a stethoscope & have a listen to all bank 1 fuel injectors to determine if one sounds different than the others.
If you come to suspect an intake manifold vacuum leak, rig a propane sniffer using an unlit propane torch, with a length of tubing attached & a sports needle on the other end as a probe & pass it along the bank one intake manifold gasket while listening for a change inidle speed or quality, or watch the scantool bank 1 fuel trim numbers for a sign of when it gets a whiff of propane, as the fuel trim should go richer. Propane is O2 sensor safe. EDIT: If you get a positive on the intake manifold leak test, maybe try re-torquing the manifold fasteners to spec in the proper sequence.
Some more trouble shooting thoughts for consideration, let us know how it goes.
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