So i hosed my car off today and sprayed in the grill a lot to get the bugs off. When i got back in the car the check engine light was on. I took it to advanced and they scanned it and i had the P0442 code. I don't know if hosing the grill did it or what but it was right after a long drive and then i hosed the front. Not sure if the temperature change did it or what. I have an 05 and i have a K&N with a Z-tube and a 5/16 motordyne spacer.

 

P0442 - Evap Control System - Small Leak (This is from the service manual)
On Board Diagnosis Logic
This diagnosis detects leaks in the EVAP purge line using engine intake manifold vacuum.
If pressure does not increase, the ECM will check for leaks in the line between the fuel tank and EVAP canister purge volume control solenoid valve, under the following “Vacuum test” conditions.
The EVAP canister vent control valve is closed to shut the EVAP purge line off. The EVAP canister purge volume control solenoid valve will then be opened to depressurize the EVAP purge line using intake manifold vacuum. After this occurs, the EVAP canister purge volume control solenoid valve will be closed.

Possible Causes:
- Incorrect fuel tank vacuum relief valve
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close.
- Foreign matter caught in fuel filler cap.
- Leak is in line between intake manifold and EVAP canister purge volume control solenoid valve.
- Foreign matter caught in EVAP canister vent control valve.
- EVAP canister or fuel tank leaks
- EVAP purge line (pipe and rubber tube) leaks
- EVAP purge line rubber tube bent
- Blocked or bent rubber tube to EVAP control system pressure sensor
- Loose or disconnected rubber tube
- EVAP canister vent control valve and the circuit
- EVAP canister purge volume control solenoid valve and the circuit
- Fuel tank temperature sensor
- O-ring of EVAP canister vent control valve is missing or damaged
- Water separator
- EVAP canister is saturated with water
- EVAP control system pressure sensor
- Fuel level sensor and the circuit
- Refueling EVAP vapor cut valve
- ORVR system leaks

If it was because of your hosing it off, you should be able to clear the code and never see it again. If you really have a problem with Evap, the code will come back and you can go from there.