NHTSA found no problem with the Toyota Corolla's steering. Instead, the problem seems to be one of simple driver preference.
NEW YORK (CNNMoney) -- Government investigators have found nothing wrong with the steering in 2009 and 2010 Toyota Corollas, the National Highway Traffic Safety Administration has concluded, closing a roughly 15 month investigation into complaints about the cars.
In February, 2010, NHTSA opened an investigation into Corolla steering following about 168 complaints. Some drivers were concerned that their cars overreacted to small steering inputs or required too much effort to keep in a lane on the highway.
After looking into the issue, NHTSA concluded there was no actual defect in the cars themselves.
"The alleged defect is driver-related 'preference' for a less sensitive on-center steering feel," NHTSA said in a preliminary closing report.
By the end of the investigation, NHTSA had found a total of 918 complaints and 4,100 warranty claims relating to steering that wandered, drifted or pulled to one side.
In June, 2010, Toyota (TM) issued a "technical service bulletin" that instructed repair shops in how to fix cars for owners who didn't like the steering feel.
As part of the repair, the cars were given a new electronic steering control module that had been programmed with a different on-center feel for when the car is being driven straight ahead.
Toyota had earlier been the subject of an extensive investigation into possible problems with electronic throttle control on many of its cars. That investigation, which involved the cooperation of the space agency NASA, found no problems with Toyota's electronic throttle control, although some critics still question that conclusion.