A few updates:
The UltraGauge did indeed show a highly inaccurate average fuel economy figure. As was mentioned in
this post, one should not rely on a ScanGauge or UltraGauge for noting fuel economy due to this sort of mod. This leads to the next update...
The MPGuino should hopefully ship today. If so, I'll install it next week.
First fillup since I did the EGR sensor modification. The results are shown below:
Date/Time | Miles | EngRunTime | Gallons | AvgSpeed (MPH) | FE (MPG) | FE (L/100km) | %diff | Notes |
2013.06.05 12:41 | 334.4 | 06:06 | 14.011 | 54.8 | 23.9 | 9.9 |
2013.06.09 16:19 | 337.9 | 07:02 | 14.333 | 48.0 | 23.6 | 10.0 | -1.2 |
2013.06.13 01:48 | 398.7 | 07:13 | 15.415 | 55.3 | 25.9 | 9.1 | 7.7 | +EGR Mod |
I think that a 7.7% increase in fuel economy is not bad.
I'm still considering installing a MAF sensor, and creating a circuit that will obtain a MAP signal for the engine computer. However, I'm also considering moving my IAT sensor so that it will be before my intake heater. This should maybe provide what I want to do, which is to advance ignition timing. Remember, a higher-than-normal EGR will require that ignition timing be advance to compensate for the higher amount of inert gas inside the combustion chamber.