O2 Diagnostic Test

[ryanstev]

My fuel economy has dropped significantly since my last fill up, I've been getting 420k from 57 litres of 95 octane (is that good?) 2 weeks ago I filled up with 98 octane from BP and reset my ECU and I've only gone around 340k on it and it's almost empty.

I have an R33 GTS25, series one, it's done 324,000k, so I'm suspecting my O2 sensor, since they have a finite lifetime and it's the most likely suspect.

I've just finished an O2 diagnostic via an ECU test (Sky Is The Limit ebook method) and have no idea what the results mean.

It's a 1 LED ECU and the book says if the LED is mostly on it's lean, mostly off it's rich.

It should flash 5 to 10 times per 10 seconds under normal conditions.

I counted the amount of flashes in 1 minute at 2000rpm, no load and got 36, so this is within the 5 to 10 times per 10 second range.

So according to that my O2 sensor is ok?

When I let my car idle the light didn't flash at all, indicating it's rich, but as soon as I applied power it flashed as normal.

Can anyone help?

Would taking my car in to Nissan for them to hook up to the Consult port give anymore information?