P0172 Code on 2016 Kia Optima 2.0 - Running Rich?

Hey all, my 2016 Kia Optima is throwing a P0172 code, and I’m trying to figure out what’s causing it. The fuel trims seem off, and I’m wondering if it could be an injector issue or maybe something with the fuel pump. Anyone dealt with this before?

P0172 usually means the engine’s running rich. Have you checked the oil for a fuel smell? Sometimes that’s a sign fuel is leaking into the oil.

Brandy said:
P0172 usually means the engine’s running rich. Have you checked the oil for a fuel smell? Sometimes that’s a sign fuel is leaking into the oil.

Yeah, good point. I had a similar issue, and it turned out the injectors were leaking. If you’re seeing an overfull oil level, it could be a leak from the injectors or even the high-pressure fuel pump.

@Johnstone
Thanks! I’ll check that out. The oil does smell like gasoline, so maybe that’s a clue. I’ll take a look at the injectors and fuel pump.

If it’s taking longer to start, that could be another clue that fuel is leaking into the cylinder. You might want to pull the plugs and check for fuel leakage with the engine off.

Stella said:
If it’s taking longer to start, that could be another clue that fuel is leaking into the cylinder. You might want to pull the plugs and check for fuel leakage with the engine off.

Got it, will do! And yeah, it’s been cranking longer lately, so this all kinda adds up. Thanks for the tip.

If the high-pressure fuel pump seal leaks, it can allow fuel into the crankcase since it’s driven by the camshaft. It’s not uncommon on these engines. Replacing the pump might be necessary.

Brad said:
If the high-pressure fuel pump seal leaks, it can allow fuel into the crankcase since it’s driven by the camshaft. It’s not uncommon on these engines. Replacing the pump might be necessary.

Yep, sounds like the pump might be the culprit if you’ve already checked the injectors. Unfortunately, it’s a bit of a design flaw.

Once you’ve checked everything, don’t forget to clear the codes and take it for a short drive. That should give you a better read on the fuel trims to see if it’s fixed.

NANCY said:
Once you’ve checked everything, don’t forget to clear the codes and take it for a short drive. That should give you a better read on the fuel trims to see if it’s fixed.

Thanks, good call! I’ll reset the codes and take it for a spin once I’ve got the parts swapped.

Let us know how it goes! I had a similar issue, and replacing the pump fixed it for me.

Dany said:
Let us know how it goes! I had a similar issue, and replacing the pump fixed it for me.

Will do, and thanks for all the advice, everyone! I’ll update once it’s all sorted.