Okay, I’m officially sat here all very pleased today. This all started when I plugged the Carsoft diagnostics in since last nights outing and noted that the DME fault code 92 had not returned – all was clean.

There were three other warnings: airbag, instrument cluster and EWS. The EWS and airbag warnings both referred to low battery voltage at some point in the past – I’m happy enough with this because I know the battery was removed at the car dealers. The instrument panel may relate to this, or being removed to have the pixels fixed, or something else (the codes aren’t especially clear). I’ve reset all these faults and read it again before I return the kit to Ian on Tuesday.

Anyway, I next decided to follow some advice I’d found on the very informative m5board.com about MAFs, their effects on power output, and how to test them.

It all seemed quite straight forward: it’s possible to get the OBC to display instantaneous fuel consumption in litres per hour (special test 4). This threw up an interesting comparison of 1.6l/h at hot idle – the same as my M3 Evo – the 328i was 1.1l/h. Anyway, rumour has it that full beans under load the engine should be shoving fuel around at something approaching 140l/h. So off I went to find out.

Accelerating hard from idle in second saw the rate rapidly rise to 50l/h but at around 3,500rpm – just when the car starts feeling less strong than Olly’s – the rate of increase slows, peaking at 99l/h just before the redline. I’d imagine that on a private circuit the same results may apply at the top of higher gears.

Now Olly had kindly donated two second hand but cleaned MAFs, so I headed home to fit them. This is indeed an easy job. New MAFs resting on the old ones:

Half way through side 1:

When I started the car it sounded a little different, but then settled to a familiar idle. Out on the road though THINGS WERE DIFFERENT. Holding back? Oh no, just a V8 roar and we’re in a different county, pumping at 125l/h – still not perfect but a whole lot better. It feels like 25% more fuel. It’s a different car now – it’s brilliant!

I’m so utterly delighted by this that I’ve even polished my exhausts in jubilation.