[nick19414]

Well this has been getting progressively worse over the past few weeks and it's getting a bit concerning.

First noticed that the engine was shuddering and the RPMs were moving up and down while sitting at traffic lights and the likes. Changing into neutral seems to make the shudders less obvious.

Since the last week the shudders have spread to when the car is slowly accelerating in low RPM ranges, typically around 1500-2000. The RPMs move up consistently below that range, shudder for a few seconds moving the revs up and down, and then continues on accelerating normally.

I've seen a few threads similar to this where the car is throwing all sorts of codes or where the shudder only occurs during idle but haven't found one like this. Is this from a misfire or a problem with the coils or the spark plugs? Are there any estimates on how much it'd cost to fix it or is it doable as a DIY?