Check engine light w/ P0455 code after Ignition Coil install

[Enze6997]

Getting a check engine light on our 04 Cayenne 3 weeks after a installation of a full new set of Ignition coils and other components that were damaged during the failure. I pulled codes and the only one is the EVAP sensor P0455. Checked the gas cap and it is tight. Any other ideas what could be going on and how much more money I am going to have to pay for a repair? Going to a shop to get codes cleared just to make sure it is not a fluke but I want to be able to ask them to check any other potential problems.

Thanks!

[Loren]

P0455 Evaporative Emission System Leak Detected (large leak)

Possible cause of fault

- Tank cap not tightened correctly, faulty or missing

- Mechanical fault in EVAP canister purge valve (does not close fully)

- Leakage diagnosis pump leaking internally (membrane) or externally

- Mechanical fault in EVAP canister shutoff valve (does not close fully when power is supplied)

- EVAP canister shutoff valve connections leaking

- Tank system (including pipes) leaking

Check the o-ring on the gas too - not just that it is tight.

[wvicary]

Perhaps you broke one of the vacuum leaks near the intake when the coils were changed out.