2002 Windstar P0306 Surging during acceleration

2002 Windstar 170K miles 3.8L

I recently replaced the spark plugs, wire and fuel filter. My wife drove from Boise to Portland without any issues. Just in the last couple of days it has started to surge / hesitate during acceleration. It doesn't seems to miss or stumble when idling, however I do recall it stumble and the rpm fluctuate when at a stop light. This seems to have improved after the wires and plugs, however it is not cured.



I pulled the codes yesterday and got 171,174 and 306. So would an injector act this way that it seems fine at idle but then cause hesitation or surging during acceleration?

Thanks

Do the p171/174 fix. Change the intake manifold bolt grommets and clean the EGR ports out. Your symptoms are pretty typical for that issue.

The clogged ports and/or vacuum leak is causing the misfire.

Certainly do the 171/174 fix.
But if you are still having surging problems on acceleration after the fix…
My van had the same problem without any codes and it ended up being a dying fuel pump. It was strong enough to pump fuel while cruising, but it started hesitating/jerking occasionally under load or climbing hills at about 140000 miles and gradually increased in frequency over time.