o.b.d.11 help

[donkeykong]

po 171 and po 174 keep coming up on reader. any help

 

[smokey]

Those are both lean codes. Check for Vacuum leaks.

 

[donkeykong]

hey smokey thanx ,i replaced 3 o2 sensors, maf. sensor, fuel filter and looked for vacuum leaks. could it be something else?

 

[dragogt]

How did you check for leaks??

 

[smokey]

What is the model,year and engine. Different trucks have certain areas that ate prone to leaks or other problems.

 

[donkeykong]

obd help

i did a visual inspection of hoses and its a 97 f-250 hd w/460 gas

 

[dragogt]

With the engine running, try using a propane torch turned on UNLIT so you can hear the gas, slowly pass it around your engine; If/ when the engine speeds up you've found your leak...

http://www.hemmings.com/mus/stories/2007/12/01/hmn_feature20.html

 

[donkeykong]

obd help

ill try that, thanx

 

[smokey]

You can also use choke and carb cleaner instead of propane . Propane works better I fasten a length of vacuum line to the propane head to make it easier it get in to the engine bay.

 

[73F100Shortbed]

The most common thing for those codes is a vacuum leak from my experience. Do what was suggested for checking and you will most likely find the problem. I'm not sure about your engine but on the 4.6L and 5.4L I've seen the rubber elbow at the pcv valve have holes in it causing these codes so check the pcv valve and hose as well as any other hoses. Sometimes the hole is so small you may not notice just by looking.

 

[godblessmud]

Focus on the bottom of the pcv hose, ive had a few leaks in the 93 351 in my ford..dont know what causes them but its a common area for some reason