All -

I have a 2007 A4 that has been great for 98K miles. Finally decided I would have my garage (non-Audi dealer) replace the plugs - reluctantly, as nothing was acting up, but I knew it was overdue. Now I'm regretting it...

Immediately after this, we started to notice once or twice a trip on daily 30 mile highway drive one or two hard stutters. I suspect a misfire. Lately, we see it a bit more - or are just learning how to induce it - tends to happen in 1500-2000 RPMs under load - esp. if pulling up a slight grade.

Since this is 100% coincidental with the plug replacement, what should I ask the garage to check? I am reading things like coil packs, ECUs, and all sorts of things speculated in similar threads. But in this case, since I know it tied to the plug replacement, I'm wondering if they put in bad plugs, wrong plugs, wrong gap, etc? Or are there possible things they should check around the coil packs that they could have disconnected or damaged?

I also saw a lot of prior threads with similar symptoms and not clear resolution, so for what it's worth, my experience suggests this issue can very much be tied to plugs!

Thanks,
Colin