Update, 03/29/2019 8:00 pm EDT: In an email to The Drive, Toyota Advanced Technology spokeswoman Tania Saldana provided this updated statement: "The safety and security of our customers is a top priority. Toyota continues to encourage involved owners to take their vehicle in to a Toyota dealer for remedy repair. While we continue to investigate reports regarding issues involving certain Scion FR-S vehicles after the engine valve spring recall remedy was completed, we have incorporated enhancements to the remedy’s technical instructions to provide additional guidance and reinforce certain aspects of the repair procedure."

Meanwhile, Subaru Director of Communications Dominick Infante tells us the company is currently working on tracking down VINs of the handful of BRZs that have had issues after the recall.

Earlier this month, we broke the story regarding a growing number of 2013 Scion FR-S and Subaru BRZ owners reporting catastrophic engine failure after bringing their cars in for a valve spring recall that was supposed to prevent catastrophic engine failure. The story centered around a registry thread on the FT86Club forums that contains a swelling list of owners—most of them of the Scion variety—that say their cars' engines are dying, often on the side of the road, shortly after doing the recall. And for full disclosure, I am one of those owners.

It appears the situation has now caught the attention the Center for Auto Safety, an advocacy group that's now calling on NHTSA, Toyota, and Subaru to put a stop to the so-called repairs. The Center's executive director, Jason Levine, wrote in an email to Automotive News: "NHTSA needs to immediately review the ongoing recall remedy to determine where the repair is going wrong. Each of these manufacturers—Toyota, Subaru, Scion—should cease recall repairs and provide all vehicle owners who have received the repair a loaner until the problem is identified."

Late last year, Subaru issued a recall on over 400,000 cars over faulty valve springs that are at risk of causing cars to stall. It affected Imprezas, Foresters, BRZs and Scion FR-Ss manufactured in 2012 and 2013. The campaign was originally triggered from 11 U.S. incidents from April 2012 to August 2015. As of Friday morning, the aforementioned forum thread contains 45 incidents of dead Boxer engines post-recall—38 Scions and seven Subarus. One of them apparently ended with an FR-S completely engulfed in flames.

Last we spoke to Toyota on the subject, it issued the following statement: "The safety and security of our customers is a top priority. We are investigating reports regarding issues involving certain Scion FR-S vehicles after the engine valve spring recall remedy was completed. No other information is available at this time."

We've followed up with the company and will update this story if it has anything more to say.

A Subaru spokesperson, meanwhile, told Automotive News: "All I can do is confirm that we have not seen any cars with engine issues caused by the recall fixes that we have conducted. We only had one person return post-recall fix. We still encourage owners to come in and complete engine repairs."

A spokesperson from NHTSA told the publication, "The National Highway Traffic Safety Administration has been in communication with the affected automakers regarding the recalls. The agency will continue to monitor all the available data to determine if there are safety implications that merit additional agency action. Consumers can register their complaints about issues with their cars at www.nhtsa.gov or by calling our vehicle hotline at 1-888-327-4236."