Hi

This one has had an intermittent fault for about 4 months, today was first time I felt problem when driving. Feels like weak mixture issue on light throttle.

no fault codes stored today, but previously had a P 420.

Plugs changed, Coil packs swooped with known good. smoke test inlet OK, fuel pressure test, no drop when fault occurring.

scoped Maf slightly low 3.9 v but runs exactly same if disconnected. ( volvo £290+vat 1 week to get so would need to be sure )

fuel trims stay within 5% even on road test, O2 sensor also stay stable. (wide band )

looking for a bit of inspiration on this, Volvo parts to expensive to guess.

Cheers Aidan