Cylinder four misfire code, now car will not start at all?

MHER

MEMBER
2017 HYUNDAI ELANTRA
2.0L
4 CYL
2WD
AUTOMATIC
92,000 MILES

Hit the brakes and car shuddered (brake issue that I need to fix) and suddenly the car started shuddering a bit and the check engine light turned on. Code was for cylinder 4 misfiring, which is what it felt like (it's had this issue before). I've replaced the ignition coils in the last year or two, and the battery is new as of a year ago. I tried reseating the ignition coil connection last night, but the shuddering persisted. Now, as of this morning, the car won't turn over. The engine sounds okay, just won't ignite, I think. I will try and get a jump tonight when I get home but any other advice?

I have a used ignition coil that should still work so that I could try and swap it out but would a single faulty ignition coil cause a car to not start at all?

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
42,909 POSTS

A bad ignition coil for #4 will not make it not start. To me it sounds like you have a catalytic converter that has fallen apart and is blocking the outlet pipe, to be sure have a helper crank the engine over while you feel the exhaust pipe outlet, it should be pulsing. If you feel nothing or a slight output but not pulsing this can be the problem. Also, you can try a small shot of starting fluid to see if it makes a difference, be sure not to spray too much. If not let's remove the exhaust manifold, (primary catalytic converter) to see if it rattles or if you can get any catalyst material out of it showing that it is no good. If you upload a short video of the engine cranking from under the hood I can see if the engine is hurt or not. You might want to remove the primary oxygen sensor to see if the engine starts as well. Check out the images (below). Please upload pictures or videos in your response to the problem so we can see what's going on.

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