Purge Valve Function

[spyderfish]

2013 STS, recently having some issues with an intermittent fault code P1175. Machine runs well, no obvious degradation. Searching knowledge from SL seems to indicate purge valve could be at fault.

Interested to hear if anyone in SL community knows what conditions and when the valve is supposed to open and close?

tia,

Gerry Fischer

[Snowbelt Spyder]

Hey Gerry. I've been searching for purge valve programing myself for 5 years. No Joy. But here's what we do know:

P1175 - system too rich Bank 2 - rear cylinder. The purge valve connects to only the rear cylinder intake. Even though a stuck open purge valve typically results in a lean condition, there is ample history here that dealers have corrected a rich condition with a purge valve replacement as well. The V-Twin has a history with cracking of the vacuum hoses on the left side of the throttle body causing a lean / rich condition, too. You've probably read plenty about that. So, what you can do right away is inspect the vacuum hoses between the throttle body and the MAP sensor. With JT's filter on, they're easy to get to. You can clamp off the line or temporarily disconnect and plug the purge valve line and see if your code clears and stays cleared. If you narrow it down to the purge valve you can replace it yourself. And if you're so inclined, do what some of us have and perform a canisterectomy. There are other things it could be, too, like O2 sensor, leaking injector, etc, anything that can cause excess fuel. If you suspect an injector, then run some cleaner through it. These are the quickest and easiest. Unfortunately, based on your mileage, your emissions warranty has run out. Otherwise, the purge valve and O2 sensor work by a dealer would be covered under that. Good Luck with it.

[billybovine]

If you decide to change out the purge valve. For the 2013 ST models. The purge system has been redesigned. The kit will come as an assembly. Purge valve looks the same as the old one. But the assembly has new formed hoses to match the new routing. A filter has been added to keep dirt out of the purge valve. Also new is a check valve. Between the purge valve and throttle body. When I changed mine out on my 2013 STL. There was crap from the charcoal canister right into the throttle body port.

[spyderfish]

Thank you for the information. I was considering removing the cannister completely and plugging the vacuum line. Sounds like a good time to do that.

If I remove the purge valve completely and plug the vacuum line to the throttle body, then, can I cap the open port on the cannister, but leave the tank vent and overflow, effectively using the cannister as a filter on the gas tank vent?

[Snowbelt Spyder]

Gerry. Removing the purge valve completely will trip a code because it's no longer plugged in electrically. What's been successful is plugging the line at the canister end of the hose and leaving the purge valve installed but basically neutralized in place. I suspect that, over time, the charcoal in the canister will become saturated and you'll pick up a gas like smell. Folks who have done this also just replace the canister with an inexpensive, universal fit type fuel filter just to keep the dirt out.

[spyderfish]

Thanx SL people for all assistance. Cannister had no fuel or fuel fumes when removed. Purge valve was open when I looked at it on the bench.
Might be a possibility of fumes from a hot soak, time will tell.

Thx again :2thumbs::2thumbs: