Engine stutter/shake

Hi and thanks for using 2CarPros.

Did this problem exist prior to replacing the spark plugs? If you scan the computer, does it indicate a specific cylinder misfire?

Here is a link you may find helpful:

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

Let me know about the questions I listed above. Also, let me know if you have scanned the computer and what the trouble codes are that are present. One last thought, this could be related to low fuel pressure as well. Have you checked or changed the filter or checked fuel pressure?

Let me know.

Thanks,

Joe

Welcome back:

Since it didn't do this before, there is a chance you didn't gap the plugs in those cylinders properly or the plugs themselves are bad. However, my first suspect is that you bumped something while working on it and created a vacuum leak. It isn't hard to do. LOL

First, confirm that the air induction tube between the air box and the throttle body is properly installed and clamped, not allowing unmetered air to enter the engine. If that is good, you need to check if any vacuum hoses were damaged or disconnected. First, do a visual inspection. If they appear good, here is a link that will help you take it to the next step. Read through it before you begin. You will be using carb cleaner to check for leaks. Be careful not to spray it directly on anything that can be exceptionally hot like an exhaust manifold. And to be honest, and don't laugh, I always have a fire extinguisher near me when I do this test, but that's your call.

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

Do these things first because I suspect it is something simple like this.

Also, since there was a bad misfire prior to replacing the plugs, there is a chance the catalytic converter was damaged and is partially plugged causing this. Take a look through these links to see if anything mirrors the symptoms. Also, I will add a link that shows how to check a converter.

https://www.2carpros.com/articles/bad-catalytic-converter-symptoms

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

Let me know what you find.

Joe