Honda Civic CEL code, what exactly is it.

[TheProfiteer]

My girlfriends 1998 Honda civic EX, just threw a check engine light and I am trying to figure out what exactly it is.

I ran the whole paper clip numeric code method.

I am getting a code #90. Evaporative emission control system.
What exactly is it, and how do I go about solving it.

Apreciate any and all advice. Thanks guys.

[EmminoDaGreat]

could be the solenoid on the intake mani, could be the gas cap, etc...

[TheProfiteer]

I replaced the gas cap, and made sure all my vacuum lines were hooked up right, they were not, so I hooked them up how they were supposed to be. There is one line I cannot hook up because it goes to some sort of sensor on the thermostat housing (not the fan switch) but the thermostat housing I have on the motor right now does not have that censor. So its just a dangly air hose, doesnt seem to be effecting performance any though.

Also they exhaust system is very rusted and and is leaking through out, could that cause it throw this code?

I also reset it real quick, I will drive it around, and we will see if it comes back.

[Barefoot]

this is about the easiest way to figure out your issue without it being a guessing game.