beechkingd

My wifes 2013 Panamera base with 95k recently had a P0455 evap large leak DTC. It initially showed as a loose gas cap fault after refilling which cleared after a power cycle, (checked the cap with no faults found). A CEL posted a few miles later with the P0455 code. I cleared the DTC and it was fine until the next fill up and the same thing repeated. I closely inspected the cap both times but ordered a new one, and after replacing that no change was noted. This continued through a couple of tanks of fuel. On the third tank and after installing a new cap it showed DTC P0455, P0175 rich bank 2, AND P0172 rich bank 1. I read a number of threads here and else where about checking the vacuum pump. I pulled the intake to inspect the vacuum lines and replaced an extremely weathered one that went to the intake butterfly on the back of the manifold. I checked the pump suction by hooking directly to the small line on the right side of the engine bay going to the tank. It showed 27" of suction with a steady needle. I T'd into the line with several hoses so I could see if there was a leak on the supply side in operation and found it still was showing -27", so no issue on the evap supply to the LDP in the back of the car or the vacuum pump. I then smoke tested the line going from the evap solenoid at the front of the engine to the charcoal canister with no faults found. I did note when checking the vacuum that the evap solenoid was clicking constantly when the engine was running and was the source of the suspected bad lifter that I'd been hearing for a year or so! I smoke tested the evap solenoid and smoke went through it both ways with very little restriction and pulled air through it with a vacuum brake bleeder. It had failed internally and was no longer sealing when powered off. I also tested the manifold vacuum at the port and found a very strange reading at idle but suspect its in a strange place in the manifold since the needle pulsed nearly full scale +- using a non-damped gauge. After replacing the evap solenoid the fault has cleared and the car idle has gone from 780 to 610 or so. The intermittent valve or lifter tick is gone too, so if you hear a valve tick put your finger on the evap solenoid to feel if it's pulsing, yours may be on the way out as well. It was very easy to replace, just two quick disconnects after removing the right engine plastic cover.

Marcus13190

You have picture to locate this valve on the engine ? And the reference ?

beechkingd

The valve is circled in red, it's located under the front plastic cover, to the right of the throttle body on the V6.

Marcus13190

Thanks