Make sure the airflow meter pot is re-installed in the same exact orientation. Problems with this item most likely to manifest at/near idle. Enrichment needed at speed is less than at idle, but fuel flow is much greater. For this reason I would check on fuel supply, e.g. weak pump. Other than fuel, ignition advance, exhaust restriction, air restriction (e.g. clogged filter) are all possibilities.

Steve

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'91 MB 190E 2.3
'08 RAV4 Ltd 3.5
'83 Lazy Daze m'home 5.7