My 2006 f150 5.4 triton has a hesatation and backfire thru the intake off and on. I hooked my reader up on live data and I get a open loop fault on fuel system . Does anyone know what that means?

 

What is the code number?

 

No codes. That's what's strange. I've had this problem off and on for awhile and when it does it's usually under 40 mph and heavy acceleration. I've just been guessing and putting more and more money on a guess! I've replaced plugs coil packs throttle body vct sensors camshaft position sensors MAF...I just decided to take a ride and check the live data and the only thing that came up was on fuel system 1 ol fault off and on

 

I googled ol fault and it says it means bad upstream o2 sensor but before I throw more money in I'd like to know if anyone knows any other problems it might be...would an o2 sensor cause my problem?

 

My first thought is an open intake valve, either through a broken valve (even carbon build up in the seat preventing full closure) or stretched/jumped chains.

 

Never heard of an 02 sensor causing a back fire...

 

Injector occasionally sticking...?

 

i'm kind of thinking the same. but i would think there would be a code if it was this

 

Not sure what the tolerance is for the PCM to trigger a fault code on that.

 

Forgot to mention I did change injectors..