Hey guys, just wanted to run this by the forum to see if anyone has experienced the same:

137k miles on my 2005 s60 T5

Just switched out my air filter for a K&N (w/ noticeable benefits!)

AND my spark plugs for the original Volvo ones bought from FCP Euro.

Here is the sequence of events after work was done yesterday:

-Drove about 2 hours - not a single problem.
-As I got off the highway and into the city looking for parking at low speeds there was a little odd revving and when I put the car into park it was revving up a bit too oddly, like it suddenly got the hiccups.
-Parked, left it for about an hour then got back in and drove around, no issues.

Today
-drove around for an hour looking for parking in the morning and as I parked again it revved again oddly (all around 1K just weird spurts).
-Parked, turned it off and out of curiosity started it up again and stalled once, then twice.
-Sat for a few minutes and tried again started up no problem.

Could this be spark plugs breaking in? Should I be concerned?

Thanks in advance.