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I have a 2006 Acura RL. I recently replaced the battery one month ago. Within the last week, the Engine Light and the Check Emissions light PO456 code came up. So far, I've checked the gas cap and taken to Auto Zone for some basic diagnostic testing. I've also changed the line hose to the purge valve. Codes are still displayed. Any and all help and input is appreciated. Thank you in advance!
P0456 is almost never a good time. :lol: This will be a challenging diagnosis without a smoke machine. But, not impossible!
Luckly, your Acura doesn't use the goofy Three Way Valve like other Honda's. This is just the tank, the canister, a vent valve and a purge valve. Do you have a scan tool with live data? There's a couple tests I can suggest if so.
Without a smoke machine, you're down to visual inspection of lines/hoses and vacuum pump testing of the purge and vent valves. I'd start with the purge valve, being easier to get to than the vent. Disconnect the vapor line (from the tank) and put the vacuum pump on the valve. Pump it up to a 5-10 inHg and see if it holds. It should. If it doesn't, recheck your pump connections before replacing the valve.
Same thing with the vent valve. The purge is normally closed, but the vent is normally open, so you'll have to either command it closed with the scan tool or power it manually to close it. Apply vacuum and watch for it to leak down. If it leaks, replace it.
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