Honda has confirmed it will bring power unit upgrades to both Red Bull Racing and Toro Rosso for the upcoming Azerbaijan Grand Prix after discovering quality control issues.
The Japanese manufacturer will be bringing updates to the V6 hybrid engine which is set to improve both reliability and performance, with a small horsepower gain.
Toro Rosso drivers Alexander Albon and Daniil Kvyat had already taken their second units following their problems in China. Kvyat had an issue in FP1, while Albon's was due to his heavy crash at the end of the final practice session.
An investigation uncovered a 'quality control' problem on Kvyat's engine after the Chinese Grand Prix.
Due to taking on a third engine component, Albon and Kvyat are certain to take grid penalties later in the season as they've reached their maximum allocation according to the regulations.
Over the course of a season, drivers are only allowed three combustion engines, Turbochargers and MGU-Hs across the 21 race season, and two of the MGU-K, Energy Store and Control Electronics.
Honda's technical director Toyoharu Tanabe said: "This weekend, we will introduce the Spec 2 version of our internal combustion engine (ICE) across all four cars right from the start of the weekend.
"One of the reasons for bringing it to this race is that we found that Kvyat’s PU problem in China was down to a quality control issue. The main benefits of Spec 2 are improved durability and life and better reliability. It also offers a slight improvement in performance."