The National Highway Traffic Safety Administration had been running an investigation on 2011 to 2013 Ford F-150 pickups over acceleration issues with the 3.5 EcoBoost engine since May, but they've decided it can be sorted through standard service updates it doesn't need to be recalled.
Apparently moisture can build up in the air coolers that feed the turbos, causing a misfire that slows the truck right down when a driver steps on the gas and pressure builds.
Ford told The Detroit News "[Our] analysis found that under those conditions, condensation could form and accumulate on the inside of the CAC tubes, which could then be ingested into the engine during particularly hard acceleration near wide-open throttle. An engine misfire of up to three cylinders could occur if the amount of condensed water released from the CAC exceeded the engine's operating threshold for water ingestion."
A total of 525 complaints were logged by the NHTSA which they cited "reduced power or drivability symptoms and not all are necessarily related to the condition created by water ingestion."
Ford was able to prove that a vehicle affected by the issue could still be driven safely, and the NHTSA concurred with their findings after running tests of their own allowing the automaker to forgo a recall.
Ford put out a technical service bulletin (TSB) that had dealers putting shields ahead of the air cooler, and say those have sorted the problem completely for 2013 F-150s. For some reason the fix was only logged at "95 percent effective for 2011-12 trucks," no word yet on what Ford's willing to do for the 5% of 2011-2012 F-150 EcoBoost owners who are still bogging.