I have a 2002 F-150 4x4 and is throwing a lean code. The code says P0174. Does anyone knows what that means?

 

Did ya check for any leaks where air could be getting into the engine?

 

p0174 means you are throwing a lean fuel code on bank 2( drivers side). check for codes again to make sure you have just the one. I f you have just the one it means you probably have a vacuum or exhasut leak on the drivers side of your engine. you can use starter fluid and spray all around the area. if hte engines revs you found the leak. I have read about a hose with an elbow on some of those motors that goes bad.....

 

so just spray every hose on the drivers side an see what happens?

 

correct.you can use carb cleaner also spray all aroound and listen for th eidle to change. spray around the exhaust also. if you can't find a leak this way it does not mean you still don't have one. but try this method first

 

Oh ok. Thanks man. I appreciate it.

 

I no have carb cleaner at the house,so you're gonna have to get some.

 

Will you guys drop it will spraying carb cleaner. That test is invalid. Honestly, has anyone on this forum every found a vacuum leak buy doing that? Thats what I thought. Here is why it doesn't work. One, the leak must be fairly substantial before this method can produce a noticeable increase in RPM. Two, the truck has an idle air controller that is already maintaining the proper RPM. If the fluid were to actually start to cause an increase, the IAC would compensate before you could detect the change. Third, I do know some mechanics who have started fires under the hood this way.

The proper way to detect leaks is with a smoke machine. It can detect very small leaks and it can detect multiple leaks.

If it were mine, I would just pull the vacuum lines, and replace them based on condition alone. If the vacuum lines did not resolve the problem, then I would pull the entire intake and redo the gaskets. If that still didn't correct the problem, then the problem is either inside the engine, or there is a misfire, or an injector is plugged.