I just picked up a 2011 Ram 1500 4.7 RWD from the auction. It has a throttle body spacer, K&N CAI and a high flow muffler. It's throwing a P0455 Large EVAP Leak code. I tried replacing the Fuel Cap with a new Mopar one, and cleared the codes but it came back. After doing some research I was considering replacing the ESIM on the tank or the Purge Valve under the battery. Is there any way to test them before buying new parts? I inspected all lines to make sure they were connected and had no cracks/ holes as well. Thanks in advance, sorry if I forgot anything this is my first thread.

 

Have it smoke tested. That should show any leaks in the system. Keep in mind, it may be a bad leak detection pump as well.....

Throttle body spacer does absolutely nothing on your engine. Someone fell for the hype, and wasted their money.

 

Agreed, HeyYou. Nor does a k&n cai. The truck comes with a cai from the factory.