Yes.
But you have to also consider that the gauge may not be 100% accurate also.
However, there is no CEL code on a 2006 model to specifically indicate low fuel pressure, so the CEL is indicative of another issue, which may or may not be related to the low fuel pressure.
Another thing to bear in mind is that around 2007, Buell changed the TPS to an different version. As I understand it, this was a "rolling change" and I dont think anyone knows when it actually came into production. The earlier style is available in the aftermarket, but if you have the later one, you may have another problem.
Also, as these bikes age, I've been reading about more issues of ECM's getting flakey and failing. I have one on my bike that does wonky things by lighting the CEL (but no code) and the bike still runs. So, just keep this in the back of your mind during diagnosis.
I'm not saying you definitively have the newer one, but its probably worth it to check out the TPS you removed and see if it has a red dot or two on it, as this will indicate the newer TPS, and you would likely have the wrong TPS on it. As these bikes are pushing 20 years old, someone may have updated the throttle body assembly to a later one (once upon a time, the entire TB assembly was cheaper than the individual injectors). The point here is, lets make sure you don't have mis-matched parts at the TB/TPS so you're not chasing a self created problem.
