It could be, but not likely. That always sets a code.
There are a few things that can go bad and not set a code, they're all mechanical and aren't monitored by a sensor.
If the FCA fails mechanically, it won't set a code. If it fails electronically, it sets a code.
If the injectors fail below the solenoid, it won't set a code. If the solenoid fails, it sets a code.
Pretty much everything else in the fuel system is monitored electronically.
What you can do is pull the FCA out (very easy, just 3 torx head bolts) and shake it back and forth. If it rattles, it's good. If it doesn't rattle, it's stuck and needs to be replaced.
The injectors are a bit harder to see. You have to pull them out and inspect them under a magnifying glass (in most cases, unless it's REALLY catastrophic). What you normally see there is a crack in the injector body or the nozzle, usually both.
These pictures are tough to tell, but here is what you see when it's a cracked injector body and nozzle. Usaully you have to use a magnifying glass or you have to put the injector on the flow bench to see if it's cracked.
You can kind of see in the first picture where the body is cracked by the fuel passage (the hole at the 5 o'clock on the face).
In the second picture, you can see the discoloration by the hole that is also in the 5 o'clock position. You can't tell in this picture, but the face of that nozzle is actually spider webbed all the way across it. Much longer and that would have be a catastrophic failure resulting in a motor rebuild.
Normally, when this happens, it's accompanied by HUGE amounts of white smoke at idle and the idle is rough. It's easy to figure out with the StarScan, all you have to do is shut down the injectors until the one you shut down causes the smoke to stop and the idle to smooth out.