1999 Intrigue 3.5 engine rough idle

The engine runs rough for about 30 seconds when first started if it sits overnite. No codes. New plugs did not solve problem.

Usual suspects come to mind(read easy to do):

1. Clean your throttle body spic and span.
2. Replace/Clean your PCV valve.
3. Replace fuel filter.
4. Replace air filter.

Almost sounds like your fuel injectors are leaky(rare) and puddling fuel on top of the cylinders. Highly unlikely though.

Is your oil level correct?

Most cars have an IACV Idle Air Control Valve or some derivation of the name(AACV). It could be really dirty.

Check out the easy things first especially if you have never cleaned them.

I clean or inspect ALL that stuff at every oil change. You know how many problems I have had in 95,000 miles? ZERO!

Let us know!