03 Pontiac Bonneville started running rough. Service engine came on and would blink then go solid again, back and forth. Local auto parts read as multiple misfire. Changed plugs and wires, same issue, took cat loose same issue. Checked coil packs with fire tester and not getting fire on coil for 1 and 4. Bought new coil, same issue. Swap coils around, of course changed wires to correct position still no fire on 1 and 4. Not sure what to change or check next. ICM?

ICM is the typical culprit.

Quick test: remove all three coils(mark their location)....disable injectors(pull 2 injector fuses or fuel pump fuse)

Each coil has two spade connectors....attach test light to 6/3 terminals...crank over...... test light should flash...then 5/2, again should flash...

When you attach to 1/4, and crank over, if the ICM is bad, it won't flash....

This ^ guy deserves a Scooby Snack.

Can I trade that in for a Polish 13?

Sure can.

Also check wires leading into the icm. One bolt to remove the connector. Check for corrosion. Reattach the connector. Look at wires as they curve into connector. Try to move the wires to have less bend as the wires go into the connector.

IRAD, that would not cause one coil not to fire....

A bit afraid to ask, but dangerously curious: What'* a Polish 13?

The GMForum bot links it to "Max Professional 3111 Furniture Polish - 13 oz." at Amazon. The Google thinks it relates to the Thirteen-Years War, . . . and Selena Gomez and a certain shade of blue nail polish.

Guessing leads me "Polish" being a type of sausage and "13" being a measurement, hence my fear of the true answer.

Maybe its 13 Polish beers?