I recently tuned my car for E85 @ RRE and lately have been getting a P0455 Code with is EVAP leak (gross). Is it the fuel that's causing the code or do I really need to replace the gas cap? How many people have the same problem after running E85?

I checked the lines but without a smoke machine I'm not going to find a crazy leak.

Thanks,
George

 

Usually means some kind of evap leak, could be the gas cap or a evap fuel line, have your gas cap tested at a smog station to eliminate that variable

 

My Evo VIII MR is having the same code issue as well because the previous owner tuned the car for E85. I am not too sure if it's the gas cap that is causing this code to come up or if there is really a fuel leak somewhere. I have heard of using a smoke machine but I am a noob when it comes to car mechanics. I live in Lancaster, CA so I do not know of any mechanic shop in the area who might be able to help me out. Any recommendations/tips?

 

The P0455 is Evaporative Emission System Leak Detected (gross leak/no flow). Either you have a large leak or a tube is clogged. This is common for vehicles when they sit and spiders like to build webs in the vent tube. Check the vent tube first. Its located on the evap canister back behind the rear bumper. You can probably google search for pictures.

Also theres and evap line that goes to the back of the intake manifold. Make sure that did not fall off or was not reinstalled after taking it apart.

Possible causes:

Loose fuel cap.
Fuel cap relief pressure is incorrect.
Fuel overflow limiter valve failed.
Purge line or vapor line is clogged.
Fuel tank, purge line or vapor line seal failed.
Evaporative emission purge solenoid valve failed.
Evaporative emission ventilation solenoid valve failed.
Fuel tank differential pressure sensor failed.
Evaporative emission canister seal is faulty.
Evaporative emission canister is clogged.

 

Same probkem with my e85 tune
However I have a aftermarket intake manifold
Would there still be a loose line at intake?

 

possibly if the lines were or were not carried over or are just laying there. Here is a pic of where they go onto the intake.