2000 Grand Voyager rough idle

I replaced the plugs and the plug wires, the 3.3 engine still has a rough idle, the problem seems a low RPM's, frequent misfires.
High humidity and rain is increasing the problem.
Since there is no distributor cap and rotor to replace, where else do I start?
thanks

Spray down the coil pack and look for arcing. A test light hooked to ground and placed next to the wires/towers can help find arcing (there can be 30,000 + volts present and it can tickle a little if it gets you!!)

If the check engine light is on there should be a code for a missfire on a specific cylinder(s). This would help narrow it down.

I just bought a 2000 with the 3.0 engine and I get the same symptoms. I went to Autozone and they did an analysis and gave me a print out. After looking at the diagnosis I decided that it might be a bad wiring connection and I basically moved wires and it repaired itself, but it came back for a short time today. It takes a while for the check engine light to reset itself however.

Some things on the diagnosis seemed wrong. I think it is still a wiring connection but I can't find it. The guy that sold me the car had it detailed which means that he power cleaned the engine unfortunately. So my hope is that if wet it will dry and I just hope their is no non-conductive corrosion.