PO172 code , possible causes ?
Thread Starter
Junior Member
Joined: Oct 2018
Posts: 19
Likes: 0
PO172 code , possible causes ?
Just recently bought a gorgeous 2003 supercrew 4x4 5.4 and it runs excellent , but im curious to know why I’m getting this code (PO172) and what I’d say not so great fuel mileage, runing rich bank one, Ive checked and replaced the air filter( was a very dirty K&N) and inspected for external fuel leaks and can’t find any vacuum leaks as of yet.
my question is, has anyone ran into this issue before and if there’s anything particular I should check ?
thanks again
also so I had another thread on a 4.6 rough idle problem I got that fixed , so I’d like to thank everyone who helped me on that.
my question is, has anyone ran into this issue before and if there’s anything particular I should check ?
thanks again
also so I had another thread on a 4.6 rough idle problem I got that fixed , so I’d like to thank everyone who helped me on that.
I'm *NOT* Skylar...
Joined: Oct 2016
Posts: 391
Likes: 54
From: Upstate New York
1) Check/change the air filter, look for air blockages
2) Check/clean the MAF sensor
3) Pull the injectors on bank 1 and see if one looks like it leaks. You may want to pull the plugs and look at them for clues.
4) Check for vacuum leaks
2) Check/clean the MAF sensor
3) Pull the injectors on bank 1 and see if one looks like it leaks. You may want to pull the plugs and look at them for clues.
4) Check for vacuum leaks
Thread Starter
Junior Member
Joined: Oct 2018
Posts: 19
Likes: 0
I just wanted to post this because something doesn’t seem right I’m not a fuel trim expert but I wanted to run this by you guys, what do you think, I will get more time this weekend to check plugs and do more testing
Trending Topics
Dude that is all over the place. Not good at all. Pull your fan belt so it doesnt turn and grab a can of propane and a torch. DO NOT LIGHT IT! Move it around all of your hoses, gaskets, and listen for your idle to change. Hopefully it will be very easy.
Senior Member
Joined: Jan 2013
Posts: 3,657
Likes: 1,029
From: KY.
If you do the propane test have the truck hooked to a scanner that reads live data and keep your eyes on the fuel trims, when they go crazy you've found the leak. If you don't use a scanner the computer will react so fast that the idle won't change, and you'll miss the vacuum leak.