Plz Help Codes P0171 & 0174 replaced elbow

[K Stokes]

Hi All,



I rec'd trouble codes P0171 & P0174; using info from the site I replaced the PCV elbow, and while I was at it cleaned my MAF, throttle body and IAC. My CEL stayed off for approximately 50 miles but has come back on. I'm thinking I have a vacuum leak somewhere...any ideas where to look or any other ideas?



I have a 2003, 4X4 with a Zabteck CAI and Sceamin' Demon coil pack. Thanks in advance for the sites help.



Ken

 

[scott degroot]

1 of 3 things more than likely happening, either the maf is bad, there i snot enough actual fuel getting to the injectors or you have a leaking intake manifold gasket...I put money on the intake leaking

 

[Greg Grimes01]

i know this sounds crazy,but i had this same problem about a month ago.checked all areas with propane for vaccum leaks .no luck cleared codes .drove about 5 miles codes are back p0171-p0174.replaced all vaccum hoses,elbows.took it to a local shop ,they could not find it.about to leave and a older gentleman told me to replace the ignition coil. i did ,NO MORE CODES. HE SAID THAT IF THE COIL IS NOT FIRING ON 1 CYL. that the comp.will not read it sometimes.but will pickup a lean mixture.which in turn will give you the codes po171-po174.running great now.GOOD LUCK!!

 

[scott degroot]

It worked in your situation for some reason but I have an issue with this. First of all if you had a bad coil there would have been other driveability issues with it. If just one cylinder was affected by a bad coil and did cause a lean condition that the pcm didn't pick up as a misfire it would have only set a lean code for one bank, if the coil was bad enough that it affected multiple cylinders then we are back to the point that other driveability symptons HAD to exsist. I know weird things, heck I had an issue once where the ac was causing cylinder #1 to misfire on a coil on plug Ford 4.6 engine...that took me 2 days to figure out.