2001 EU Honda Civic, 5door hatch. 87k miles on clock, no mods. Recent 85k service by dealership.

When the idle drops it is usually at the end of the drive home, some 25miles. So the engine is nice and warm. The idle bounces between 200 ish to 600rpm. This was happening before my service.

It doesn’t happen every time I use the car, which makes me think it may be the throttle body. Would normal carb cleaner work?

Any advances on this?

. Clean throttle plate, throttle body, and upper and lower ports.

. Clean/replace Idle Air Control Valve (IACV):

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-7.html#post1054149

. Clean air box and replace air filter.