Didn't I answer this? To many conversations on to many different groups. Test for vac leaks with carb cleaner, spray on all lines and connections, don't forget the EGR tube. Any changes in RPM and you have a leak.
Check all your plug wires. Make sure they are not touching a ground. Also check back wires, 4 and 6 are good for this. Make sure they are not touching the O2 sensor wire. Make sure all wires are on tight.
Pull plugs and inspect, post pictures if you find anything odd.
Most of the time, random misfires are caused by these problems.
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1997,1998,2000,2005 year confused Bonneville SSExi. Stock? ish.
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