So I have been searching for what is the source of my P1452 code that keeps coming back on, I have reset it, it stays off for a month or so, then comes back. I have reset it twice, and now it just came back on. Most of my searching for ideas talked about a three amigos situation, which it not what I have. I have been thinking it is related to this part:
Fuel Vapor Leak Detection Pump; Leak Diagnostic Pump
its not too expensive (around $60) and sits under the vehicle along the passengers side frame rail about half way back. Not sure if that is the right place to start, but I hate to start throwing parts at it, and wanted to see if anyone knows more about this than my code reader is telling me

 

Hi, did you ever figure this out? My new truck is constantly throwing the P1451 code. I replaced the gas cap and tightened it down super hard. Still got the P1451 code.

 

Did you clean the spout prior to the new gas cap? I cleaned mine with a scotch brite pad, tighten the gas cap to one click, and never got the code again.

 

Thanks for the tip. So I tried to clean out the gas tank spout but the cap still has a hard time going in. I then WD40'd the cap and worked it back and forth until it could get a "good" seal. I drove the rover for a couple hundred miles no pending code so it seemed to be fixed.

Then I got gas. And it has a difficult time seating on 100% and the code is back. Not sure what to do except lube up the cap again...

 

The code is for Evaporative Control System Pressure Sensor Low Input. start by looking at the sensor and wiring for it. It's located on top of the fuel tank. To access pull up carpet in trunk and there is an access port. When I bought it my truck throwing that code and failing emissions tests because of it so I got it really cheap, issue was as simple as the wiring on the connector was corroded.

 

Looks like a mouse had those wires for lunch.

 

The wiring harness looked clean and secure. I have a parts car 2000 disco II and thinking about pulling the leak detection pump and replacing it on this one and seeing if it helps. Stupid code, why did you have to clear and get my hopes up!!! Literally no pending or confirmed for 200 miles, take gas cap off and back on, boom code again.

 

FYI I fixed the issue, I as well installed a new Leak Detection Pump. Just bought one off ebay for like $50. Driving it around for ~300 miles or so, no pending yet.

Answer: Get a new leak detection pump if the code says you have a fault in the leak detection pump