Will not start, running lean, cylinder misfire?

KGUNDERSEN21

MEMBER
2011 HYUNDAI SONATA
2.4L
4 CYL
2WD
AUTOMATIC
180,000 MILES

The car listed above is a GLS, 2.4L L4.180,000 miles, approximately 50,000 on the engine that was replaced by Hyundai under a recall.
Car was hard to start, running slightly rough at idle, and then CEL came on. Codes are P2191 (System Too Lean at Higher Load Bank 1) and P0301 (misfire cylinder 1). I don't have the freeze-frame data since it was someone else that pulled the codes. Today the car won't start--it cranks hard and when it does finally start, it immediately coughs, sputters, and shuts off. Spark plugs are not worn or fouled. Ignition coil ohms are within spec. Injector ohms are within spec. I'm thinking a clogged injector or maybe bad wiring to the ignition coil? MAP sensor? Are there other things I can check, keeping in mind that the car doesn't start?

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,755 POSTS

Hi,

Since we have a misfire and a lean fuel mixture, I would start by checking for large vacuum leaks and fuel pressure. Have you done that yet? If not, give it a check.

Here are two links that explain how it's done:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Let me know what you find or if you have already done that.

Take care,

Joe