2009 GS SM5, running roughly after oil change - any ideas?

[BajaRon]

All parts arrived and I got to work.

Installed new spark plugs/wires from Bajaron, very nice quality, came quicky and worth the money in my opinion. Definitely an upgrade from the OEM and going to the Iridiums is a smart decision to make if you'll be in there anyways. (Vacuum lines as well.)

New oil pressure switch/sensor installed. $14 part for OEM, very well priced I'd say. Didn't drain all the oil out, just removed lower panel and had a funnel/oil bottle handy and worked perfectly to catch the very little bit that leaked out. P0520 code was gone right when I turned the key on, without even starting the bike.

Now that she ran flawlessly it was time to go warm her up; took her out for a ride and pulled back into the shop; let idle for 1 minute and checked oil level. Tad low, added very little and was good to go. This is Why it is very important to have the oil at temp and check it properly, while cold there was not a level shown.

Everything checks out now, main problems were spark plug wires and oil pressure switch. Had some spare LED bulbs laying around, so decided to throw them in the tail/brake lights. Caused it to throw codes and go into limp home mode. While fun to ride, she's definitely a picky machine.

Thanks to all who pitched in some comments/recommendations. Hopefully this information comes to use to help save some riders money doing it at home instead of the dealership.

AWESOME! Looks like you nailed it. There are some other DIY mods that can make the 998 much less issue prone. As far as lighting (or any electronic add-ons), you'll find the Spyder to be very electrically sensitive. Cut & Splice wiring can give you issues, as well as lighting that is not compatible. Usually, this includes cheap lighting kits. It's well worth the extra money to get lights that are proven compatible with your Spyder. (Don't ask me how I know!)