01 Bonneville sle missind and studdering constantly at operating temperature, have a emissions code turned out to be loose gas cap fixed that still missing, could upper intake?
If a complete tune-up has not corrected this, then yes, common problem on those, maybe try to tighten it up? See if it makes a difference...
Tune up recommended if it has been 30-50K miles or 5 years since the last time.
Turned out to be failing ignition module.
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