Honda's F1 technical director Toyoharu Tanabe says that the Japanese squad are looking into the issue that ended Daniil Kvyat's race during the recent Italian Grand Prix.
Kvyat was forced to retire with an oil leak, retiring from a promising position as Honda introduced the Spec-4 engines for all four drivers.
Tanabe told RACER: "We had to stop the car, which was disappointing because I’m sure we were on for some big points, but now we will try and make up for it in Singapore.
"Currently, along with the Toro Rosso engineers, we are investigating the exact nature and location of the oil leak.
“We still acquired plenty of data from running all four cars with our Spec 4 power unit, which will be useful as we prepare for Singapore.
"The data collected looks good, but when you talk about competitiveness it's harder to say. I would like to see the Singapore data with a lot of downward pressure, then we will have a clearer picture of our position."