Likely the FSS was never reset after service.
I would DIY (if possible):
- change oil & filter (Synthetic 0w-40 and fleece (not paper) filter)
- Change cabin filter
- change air filters (k&n as long as you are doing it)
- reset FSS
No need for plugs at this point.
This will give you a good starting point.
FFS RESET PROCEDURE:
1. Turn key to the ON/RUN position.
2. Within one second press the ****/button twice.
3. The present status for days or distance is displayed.
Within 10 seconds turn the key to OFF/
LOCK.
4. Press and hold the ****/button, while turning
the key to ON/RUN again. The present status for
days or distance is displayed once more. Continue
to hold the ****/button.
After approximately 10 seconds, a signal sounds and
the display shows 7,000 miles (Canada: 11,000 km) for
approximately 10 seconds.
5. Release the ****/button.
