For 95 V-6 the coil generates a tach signal which it sends back to the cluster. That must be a separate circuit because I've heard of a couple cases where a flaky tach was cured by replacing the coil. And the engines ran just fine.

Only the first couple years of the V-6 were like that. Older 4-cyl tach signal is created by the ignitor. Later (98+) the tach signal is created by the ECU.

jrw1818, you haven't said what year is YOUR car?

I think the EGR is a separate problem.