ticks and a stutter

[flipper]

Lately my boxster has developed 2 things,

1. It has a small intermittent ticking noise, sounds like a valve. It does not do it all the time and it is very faint. Is some valve noise to be expected?

2. right after cleaning and oiling my K&N air filter, I noticed a rough spot at about 2400 rpms. I took the K&N out and replaced it with the OEM filter.
Think its the MAF? and is it easy to clean?

Thanks all
Shawn