Lexus P0440 Code Causes Engine Light

[ray]

Hello All,

I have an issue with my CEL (Check Engine Light) popping up intermittently. This is in result of the ECM throwing a P0440 Code. Apparently, this is due to issues with the Vapor Canister, maybe a Vapor Pressure Sensor? Can this be caused by something as simple as a fuel tank cap not tightened or needing replacement?

I just would like to know where I can start to troubleshoot why I would all of a sudden have vapor canister issues. I am trying not to just throw a new canister at it and that not be the problem.

A little about the car : 1996 Lexus ES300 with 200,000 miles. Recently changed o2 sensors which caused the CEL to stay on constantly. Takes about a week for the CEL to come back on after clearing the code for this new Vapor Canister issue.

Any ideas?

Topic

[ray]

The latest and greatest…

I had a harness clip loose on one of the ignition coil packs (namely Cylinder 1).
Ever since I had the harness clip replaced the check engine light has never returned.

Even though it threw a P0440 code, could it have all been caused my a slight misfire or circuit issue caused by the harness clip being loose?

Would like to think this engine light will never light up again for this reason…

Let me know what you guys think….

[Bill]

P0 440 = EVAP leak somewhere. It could be caused by something a simple as a gas cap that’s not sealing.

A fuel cap is probably the cheapest part to replace.

It could also be caused by a split hose or loose connection within the EVAP system.

[ray]

Bought a new fuel cap, check all connections and hoses.

The engine light still came on. I recently replaced a harness clip on the Cylinder 1 ignitor coil.

I am leaning towards the ignitor coil being the issue.

[Author]

Replies