P0442 Evap Emission Control Small Leak Detected
Evaporative Emission Control System Leak Detected (small leak)
What does that mean?
This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to OBD-II equipped vehicles. Although generic, the specific repair steps may vary depending on make/model.
The vehicle's PCM (powertrain control module) tests the evaporative emissions (EVAP) system for large and small leaks among other conditions. In the case of this DTC, it indicates a fuel vapor leak in the EVAP control system. It means a very small leak has been detected. In fact, the leak can be from a hole as small as 0.04" in diameter. The (EVAP) emission control system prevents the escape of fuel vapors from a vehicle's fuel system.
Fuel vapors are routed by hoses to a charcoal canister for storage. Later, when the engine is running a purge control valve opens allowing intake vacuum to siphon the fuel vapors into the engine.
The only thing you will notice is the Malfunction Indicator Lamp (MIL) a.k.a. Check Engine Light will be illuminated. You likely won't notice any drivability problems although sometimes a fuel odor may be noticed.
A code P0442 most likely means one or more of the following has happened:
- A loose or improperly affixed gas cap
- A non-conforming gas cap (i.e. not factory/original brand)
- A small leak/hole in a fuel vapor hose/tube
- Other small leak in EVAP system
- Faulty vent o-ring seal
- Defective vent valve
- Defective purge valve
- Defective leak detection pump
With a P0442, the most common repair is to:
- Remove and reinstall the gas cap, clear the codes, and drive for a day and see if the codes come back.
- Otherwise, replace the gas cap (we recommend an OEM not aftermarket part), or
- Inspect the EVAP system for cuts/holes in tubes/hoses
More advanced troubleshooting steps include:
- Using an advanced scan tool, perform an EVAP leak test
- Verify operation of the EVAP purge solenoid / valve
- Perform a smoke test to see where the leak is
Generally there are vehicle and model specific procedures for proper diagnosis of this DTC.
Related P0442 DTC Discussions
- P0455 and P0442 on 2001 Dodge Ram 4x4 Quad
After attaching my scan tool I retrieved the DTC P0455 and P0442 which point to both a large and small evap systems leak. Why would I have both instead of either one or the other? If I had a large leak wouldn't that overshadow the small leak, or does both automatically register whenever the large ...
- 2001 Dodge Grand Caravan - Codes 1684, P0442 & P0455
2001 Dodge Grand Caravan, 3.3L V6 with aprox 97K miles, check engine light is on again for the fourth time in less than 2 months. The first time the codes were 1684 & P0456, we changed the gas cap to a new one and had the codes reset. The second time was 2 days later, the codes were again ...
- 03 Dodge Caravan w/ P0442 and P0455 codes
I have a 2003 caravan that I purchased used and found out it is out of warranty as of April 1... isn't that always the case. It has just over 29,000 miles. The check engine light came on and the code it was diagnosed with is P0442 and P0455. The place we took it to did not have the smoke mach...
- P0455 Dodge Dakota P0442
I have checked the vacuum lines running from the control unit to the tank and do not find any cracks etc. I have used a vacuum pump to check the system, small line to the control unit from a tap in the line. It will hold vacuum to the control unit. From the same tap to the tank I cannot get any v...
- P0442 - Recurring problem
I have a 2001 Chrysler Sebring convertable, 2.7L. Engine light came on recently with P1684 and P0442. I purchased a new Mopar gas cap and had the system smoke tested. Mech (good rep but not a Chrysler dealership) said they used a smoke machine to pressure test the system. After smoke, pressure w...
- Mazda Protege 2000 P0171, P0442
I have a 2000 Mazda Protege, 1.6L with 5 speed manual transmission @ 150,000 kms. It is showing codes P0171 and P0442 which means system too lean and small EVAP air leak. The car performs well on cold start up but once warm it looses power. Idling is good and mileage is fine. I see from various foru...
- P0442 on 1998 Dodge Dakota
I've got a '98 Dakota and have been troubleshooting a P0442 (evap sys leak) code for over a month now. Here's what I've tried; 1) I replaced the gas cap - light back on in a couple days. 2) I had it smoke tested at a local shop - They found no leak but told me to take it to a dealer to test the...
- P0442 small & P0455 large evap emission control sys leak
I have a 2002 Dodge Ram 1500 with 3.7 L v6 & automatic trans. It has 38K Miles check engin light is on. The OBD scaner shows the following 2 codes: 1. P0442 evap emission control system leak (small). 2. P0455 evap emission control system leak (large). The truck runs Ok. What are the possib...
- Dodge Caravan 2003 P1684 P0442 P0455 P0456
Check engine light came on a couple of weeks ago. At first it was just the battery code P1684 and the small evap code P0442. Now the other two codes are showing as well. What are the chances that this is only a gas cap issue? I just replaced the cap but have not driven it yet. Since I am getting al...
- 2001 Olds Alero Code P0442
I need some help. I don't know to much about cars, I have a 2001 Oldsmobile Alero and the service engine light came on. My brother in law checked the car and the code P0442 came up. Something about a leak of some kind. If anyone could throw some more information my way that would be great. Thank you...
Need more help with a p0442 code?
If you still need help regarding the P0442 trouble code, please post your question in our FREE car repair forums.
NOTE: This information is presented for information purposes only. It is not intended as repair advice and we are not responsible for any actions you take on any vehicle. All information on this site is copyright protected.