Check Engine P0455

I have an Infiniti i35 and I keep getting the check engine light P0455 (gross emissions leak). I’ve replaced the gas cap to make sure that isn’t the problem and after I replaced it the problem continued. What should I do and in the mean time before I get if fixed is there any effect to the car (like lower gas mileage or engine damage)?

after I replaced it the problem continued.

Did you reset the CEL?

About the only problem that might be encountered when driving with a gross evap leak, is unfiltered air entering the intake. This could be a problem if there is a rotten hose under the car and it’s driven a lot on dirt roads.

What you should do depends on how handy you are. Running from your gas tank, up the underside of the car and into the engine area are your evaporation lines. (Could be a line rather than multiple ones). They just carry gas fumes from the tank to and underhood system that feeds the fumes into the engine to be burned rather than venting to the atmosphere.

The fumes run through a charcoal canister (storage device) and flow is likely controlled by a sensor and solenoid. (I don’t know the specifics of the Infiniti system).

So you have a series of vacuum lines from the gas tank, running through some other things, and ending up somewhere on your intake manifold or throttle body or someplace like that.

Someone needs to check out the whole set of vacuum lines and connections. If you’re handy and ambitious “someone” might be you. If not, then you just take it to a shop.

You’re almost lucky in that a “gross” leak will be a lot easier to find then small leak (you can also get that kind of code). You might get lucky enough to just pop the hood, look carefully and find a disconnected or broken line.