Had one on my '07. Had an off-idle stumble, on hot days it pinged when at highway speeds on flat roads, and heavy pinging between 2800-3500 rpm on heavy acceleration. V&H tech support was great- tried all kinds of solutions, but never was able to resolve the issues. They finally told me they couldn't figure out the stumble or flat road pinging, and that all Harleys pinged at 2800-3500 rpm. It did nothing for controlling heat at idle either- per V&H the FP doesn't start managing fuel till you're off-idle. Sold it & got Xied's and no more stumble, no more pinging, and cooler at idle. For those that it works for I think it's a great piece of equipment, but for me it didn't work.

 

I had the same probs with my 2010 Street Glide with the Fuelpak. If you remove the header pipe (cat) and replace with a pipe without the cat, you need a fuel management system that will adjust the timing. I have the V&H Power Duals with Crusher mufflers and the Fuelpak would not work correctly. It ran like sheet. I called V&H numerous times and they had no answer for my prob.

I got a TTS and loaded the proper map and it runs GREAT. You need a TTS, Power Commander or a tuner that can adjust the timing on a 2010 or later. I found that HD had to adjust the timing to compensate for the cat. Changing the the header pipe requires the change in timing to re-adjust to the removal of the cat.

I am not bashing the Fuelpak, I also have an 05 Softail with the Fuelpak and it runs great. It seems this problem is only with the models with cats in the header pipes.

 

There is a great Youtube video on setting/adjusting your fuelpak. It covers and shows the throttle calibration step...fyi