3.4 swap misfiring. thinking coil packs
 

whats best way to test coil packs.

Whats best way to know what one is going out.

Or should i change all 3 out at once.

And whats best coil pack for 3.4

Did you change your timing belt? not missed a tooth?

its been running great for last 6months just started running funny in the last month.

Got any code? Sounds like something the folks at the 3rd gen can help.

How old are the plugs wires? Maybe one has a crack and spark is leaking through it. Condition of spark plugs? A vacuum leak or a vacuum hose is loose?

Mine misfired because of plugs. Didn't even look bad. You can test the primary and secondary resistances of your coil packs. It's very small so don't forget to touch your leads together and subtract that resistance.

in last month. ive changed plugs new wire new coil packs. Ive put a new rear o2 sensor.

can vaccum really make a misfire?

hook up the obd2 and see if it tells you what cylinder is misfiring. Or atleast under what conditions. Open loop/closed loop.