One of the Innovate AFR gauges, or an AEM is way more then just a gauge. They have a proper UEGO wideband sensor. If you put it in your line of site, eg, just to the side of the cluster on the dash, you should be able to see whats happening.
You need to know what air/fuel ratio to expect and when.

Why don't you just take it to MMS or someone else who sells Walbro's and get them to have a look at it. Make sure its the real deal

__________________
Its just the internet dude, its not real.
F.B. Racing
01 WRX (STI badged)
2010 XR5 Focus
06 Impreza Hatch 2.0i