So I decided to get the old 94 3.3 liter intrepid running and out of my garage. Put a fresh set of tires, battery, and a fresh tank of gas and all was good.....for a little bit. I decided to change the oil, new air filter, and change the plugs. I had no clue how old the plugs were or the last time they were changed. I figure it couldnt hurt.

During the process of pulling the spark plug cable, a couple appeared to not have the silicone installed under the boot. Of course, I pulled a couple of the ends out of the boot trying to remove. I ended up replacing the spark plug wires. I did this carefully one at a time. Installed some bosch platinum's fired it up and now runs a little ruff with a very small backfire or pop at idle.

I have triple checked the plugs and ensured they were snapped onto the plug and onto the coil correctly. The car is not displaying a check engine light either.

I am lost! Any suggestions? Are these engines so delicate that premium plugs can cause this and OEM are required?

 

Premium plug doesn't hurt, But the problem is Dodge Engine doesn't Like Bosch, there are even Tech Tips/TSB on plugs for certain engine. Throw them out and go back to OEM Champion plugs.