P0155: O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)
P0301: Cylinder 1 Misfire Detected
P0401: Exhaust Gas Recirculation Flow Insufficient Detected
SOURCE: rough Idle trough1500 RPM with trouble
A code P0303 may mean that one or more of the following has happened:
Possible Solutions
If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.
If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.
A. P0401 "Exhaust Gas Recirculation Flow Insufficient Detected" that there is not enough exhaust gas being admitted to the engine.
There are a number of things you can check, and others you need a scan tool to check.
What you can do is check for vacuum to the EGR valve. You can remove the EGR valve and see if it is stuck closed. Test it with a hand vacuum pump and see if it opens smoothly. Check the EGR valve orifice and make sure it is free and clear. Check and clean the EGR passages in the going to and from the EGR valve.
If this checks out, then the Differential Pressure Feedback EGR system will need to be scanned to check the EGR sensors and switches
A code P0301 may mean that one or more of the following has happened:
384 views
Usually answered in minutes!
×