[75aces]

Double check the gap on the electrode armature to make sure it’s in spec.

A test you can perform is to pull the plug and attach it to the coil pack and lay it on the valve cover. Crank the engine over to see what color the spark is.

There’s a spring in the coil pack that stretches over time. Try swapping coil pack and plug to verify its moving to another cylinder.

 

[new echo owner]

Swap the coil and spark plug to other cylinders, coil in one, plug in another; see if the issue follow with the parts to other cylinders!

 

[judedude]

Sounds like it is a coil pack. Same happened to me. Ran really rough at low speeds but was able to limp it home.

 

[hestera2]

I swapped coil pack from 1 to 2 and spark plug from 1 to 3. Same code popped.

 

[hestera2]

Swap the coil and spark plug to other cylinders, coil in one, plug in another; see if the issue follow with the parts to other cylinders!

 

[new echo owner]

Swapping the parts around is mainly to determine what may be causing the code!
If the code went with the part to the cylinder where it went to, then your issue is with the part and not the cylinder itself.
In your case, it looks like it is the cylinder since you are getting the same code! Would start with a compression test!
What is the mileage of the vehicle and condition?

 

[corollacoaster]

P0301 means cylinder #1 is not firing. Your test swapping coils and spark plugs showed no change, so it isn't a spark problem. Test the fuel injector and compression.

 

[hestera2]

Update: after watching a few other videos, I went back and unhooked the coils while the engine was running. The 1st coil was bad and didn't make an obvious difference in the engine idle while the other 3 did. I replaced the coil and it's back to normal. Thanks everyone for the help! This was a big learning experience.

 

[new echo owner]

Huh? You swap the parts back? Something doesn't sound right!
If the coil was bad, you would have get P0302 when you moved it to #2 cylinder!

 

[75aces]

This issue has happened to me before. The time it happened, I got a P0304, but swapped with cylinder 1. Cleared the code and got both P0301 and 304.

At first when I removed the plug from cylinder 4, I hadn’t noticed that the electrode left the chat. Tried swapping the coil packs too and got same results. Found oil buildup in the spark plug tube seals. Replaced the seals and valve cover gasket, along with new set of plugs and coils.

 

[RT27]

Double check the gap on the electrode armature to make sure it’s in spec.

A test you can perform is to pull the plug and attach it to the coil pack and lay it on the valve cover. Crank the engine over to see what color the spark is.

There’s a spring in the coil pack that stretches over time. Try swapping coil pack and plug to verify its moving to another cylinder.

Check engine codes first, use it to track issue mine did similar with knock sensor gone bad

 

[75aces]

Check engine codes first, use it to track issue mine did similar with knock sensor gone bad

Did you get misfire with knock sensor?

 

[RT27]

Did you get misfire with knock sensor?

Yes ran rough and lost power