Replacing spark plugs

It shouldn't be hard to find one. Pay attention to the torque range, lowest to highest, in the description of the tool. You want one where the low end of the range is something less than 15 foot pounds and the high end is something more.

For the mechanical click-type ones, it's also better to use a lower-ranged one (where 15 foot pounds is not near the bottom of its range) instead of a higher-ranged one (the tool can be less accurate when set in the extreme lower part of its range).

The simplest type, with a beam that points to numbers on a scale, is kind of foolproof, except that it's hard to use in positions where you can't be watching the needle and scale straight-on the whole time. That's really why the clicky or beepy kinds became more popular.

But first it might be worth thinking about various reasons, besides plugs, why your 197k car could be shaking while accelerating. (What is the car, by the way? Your profile says 2009, but you've posted here in the Gen 3 forum, for 2010 through 2015.)

 

IMHO; you should get a friend to help you out on the spark plug change and EGR clean-out. It's a "blind-stick" going into an aluminum head - really easy to cross-thread for someone that doesn't do this kind of work and doesn't have a "feel" for it. The best rule of thumb is, hand twist the spark plug all the way down and torque it down the last few turns. If you force it down with tools, there's a good chance you'll cross-thread it.

Just my two cents....

 

That's one among a bunch of things that can happen, though I'm not sure it's the first thing I'd think about with your symptoms. The valve can also stick open, which could give some roughness symptoms, but you'd be noticing those at idle.

A common contributor to rough running at mid-loads, like when you're accelerating but not aggressively, would be clogging of the EGR passages in the intake manifold. That would come kind of early in my list to check.

 

Make sure you avoid knock-off spark plugs from places like Amazon or eBay.