CEL keeps coming on...

[Gennycide]

2012 Genesis 4.6 that I have had minimal issues with throughout my ownership. But recently, I've had one reoccurring problem.

Back in Nov 2023, the CEL came on. Went to my local auto parts store to use their scan tool. Came back as a PCV issue. I ordered a replacement valve, installed it, CEL immediately went off and everything was fine.

Recently the CEL came back on. Went to check the code again and came back with the same issue. Luckily, I was in a area with more resources than my normal area and I was able to find a dealership that had one in stock. Replaced it, but this time the CEL did not immediately turn off. It took a couple of cycles and some driving, but it did. After about 400+ miles of driving the CEL came back on. Same issue came back when I went to check the code. Replaced again with a spare PCV that I had from the first incident. CEL immediately turned off and everything was fine.

This morning, CEL came back on. Damn it! The replacement lasted about a week. Quick note when this happens, I cannot tell that there is anything wrong with the vehicle. No weird noises, no rough idle, no loss of power. When I went to check the code, the CEL had turned off. Hmm... But I still used the tool to see if anything would show. Came back with: P2191 System Too Lean at Higher Load Bank 1

Does anyone have any knowledge of what this could possibly be? I don't believe that all of the PCV valves have gone bad that fast, but maybe? One thing I have noticed when I changed the PCV valve is that there is some oil around the threading and on the valve itself. Is this normal? I believe my next step is to get a more detailed diagnostic check, but I wanted to check here first. Maybe a fellow Genesis owner has dealt with this before and would have some helpful knowledge. Thanks!

 

[Charlie1982]

How many miles are on the car? Have you owned it since new?

 

[Gennycide]

How many miles are on the car? Have you owned it since new?

211114 right now. I purchased the car in 2016. The CEL has been off ever since I posted, and everything with the car seems fine. I haven't been able to get it to the shop for a diagnostic check yet, but it is definitely a priority and will be done when I'm available to do so.

 

[Charlie1982]

211114 right now. I purchased the car in 2016. The CEL has been off ever since I posted, and everything with the car seems fine. I haven't been able to get it to the shop for a diagnostic check yet, but it is definitely a priority and will be done when I'm available to do so.

Let us know what you find out. I'm curious what would make it throw a "lean" code. With that many miles on the car, it wouldn't surprise me if that code is a separate issue from your PCV episodes...

 

[Gunkk]

An air leak between the MAF and O2 sensors can result in a lean code. If more air than expected enters the engine anywhere in the sensor-monitored part of the engine, the ECU can see it and can throw a lean code. A stuck-open PCV could do it of course, as could about a dozen other things (old cracked hoses, loose/broken fittings, failed parts, leaky gaskets, etc.).

Likewise, insufficient fuel can do it too. However, while it is possible for a fueling problem to present a lean code on modern cars, the way insufficient fuel presents itself rarely (if ever) shows up as a simple global lean code on an otherwise well running car. Typically it's a bad injector with a single cylinder misfire code, or the entire car won't idle or run well (bad gas, plugged fuel filter), or won't run at all (dead fuel pump).

Our cars do have a 3-strikes and you're out kind of logic with the CEL, where some intermittent faults that illuminate the CEL will clear themselves after three key-on engine running cycles if the fault does not repeat. I've seen it a few times on my cars. And there's nothing to show in the stored code history for when it does. Gotta catch it in the act.

So Gennycide you may have a marginally small intermittent leak somewhere else other than the PCV valve itself. For a DIY diagnosis, if you have an OBD2, try to pull the code when the light is on. If the OBD2 tool can read dynamic engine data from the ECU, check your fuel trims with the engine on. If ST%+LT% > 10% then you almost certainly have an air leak. A smoke test will almost always pinpoint it.