Alright so here's the deal my truck is throwing 2 codes P0171 system lean (Bank 1) and P0174 system lean (Bank 2). I'm trying to figure out what it is. now keep in mind i go to school for auto tech. my teacher seems to think its the MAF and i've had a few other people tell me the samething. but i've also had people tell me its a vaccum leak. i figure i would turn you guys. What do you think it is? My truck is 4.0 sohc

 

Nothing at all guys

 

The 4.0 has a tube that runs from the PCV valve at the back of the driver side valve cover to the passenger side of the intake manifold. There is a rubber elbow that tends to crack. Check that tube man. I'll try to find a pic of it.

 

You can change the elbow with an aftermarket elbow. Ford sells the whole tube for about $30-40.

https://www.ranger-forums.com/forum2...ommon-cel.html

 

hey man thanks for the info and you were right, that elbow is cracked....you just saved me alot of money right there lol.

 

You should read this thread, the mods should have stickied this:
https://www.ranger-forums.com/forum2...ues-p0171.html

 

No prob man. That may not be your problem but here is hoping it is.

 

i'm gonna hope thats what it is....me and my teacher had it narrowed down to either the MAF or a vacuum leak...and thats a pretty big vacuum leak.

 

If your teacher understood STFT's he could easily tell the difference.

 

I had that same vacuum leak with those codes last summer. Cracked hose elbow.

 

I never acutally took my truck into the shop to connect a scanner up to it...we never looked at Short Term Fuel Trim....just told him the problem i was having

 

my truck is throwing the same codes at me. I'm gonna go out and check for a cracked hose. I'm keeping my fingers crossed.

 

low and behold, i found a cracked elbow.

 

yupp i was at school and found some heater hose and used that to fix the problem...its a really easy fix tho