Error pam authentication service cannot retrieve authentication info for illegal userApr 01, 2019 · P0304 is a relatively common trouble code with any vehicle, that includes the Mitsubishi Outlander. It’s and OBD2 code and stands for: P0304: Misfire Detected → Cylinder 4. P0304 is certainly a cause for concern, and should be considered a threat to the drivability your Outlander. 00 cash register lab| P0304 MITSUBISHI code tech notes The P0304 code means that the cylinder 4 is misfiring or is randomly misfiring. Start by checking for intake leaks and if no leaks are found the next step is to replace the spark plugs on cylinder 4. If the problem persists more tests needs to be done to diagnose problem, see "Possible Causes"