P0401 MERCURY - Exhaust Gas Recirculation Flow Insufficient Detected...Possible causes; EGR passage clogged, Faulty EGR Vacuum Modulator Valve, Faulty EGR Valve, Faulty EGR solenoid valve, EGR solenoid valve harness is open or shorted, EGR solenoid valve circuit poor electrical connection, Dead (Weak) battery, Faulty EGR temperature sensor and circuit, Exhaust gas leaks...EGR flow malfunction could be caused by a clogged EGR valve or EGR tube. Before replacing any parts try cleaning the EGR valve, tube and passages. If the tubes are clean you may have to replaced the EGR Pressure sensor to fix the problem.......P1131 MERCURY - Lack of Upstream Heated Oxygen Sensor Switch Sensor Indicates Lean Bank 1...Possible causes; Faulty Upstream Oxygen Sensor Bank 1, Fuel pressure high or low, MAF sensor dirty/defective, Vacuum leak on engine, Leaking fuel injector or fuel pressure regulator, Faulty Powertrain Control Module (PCM)...The code means that the Powertrain Control Module (PCM) has detected a lean system, which means that there is either not enough fuel or and excessive amount of air in the system. Start by checking for vacuum leaks........P1132 MERCURY - Lack of Upstream Heated Oxygen Sensor Switch Sensor Indicates Rich Bank 1...Possible causes; Faulty Upstream Oxygen Sensor Bank 1, Fuel pressure high or low, MAF sensor dirty/defective, Vacuum leak on engine, Leaking fuel injector or fuel pressure regulator, Faulty Powertrain Control Module (PCM).......P0306 MERCURY - Cylinder 6 Misfire Detected...Possible causes; Faulty spark plug 6, Clogged or faulty fuel injector 6, Faulty ignition coil 6, Fuel injector 6 harness is open or shorted, Fuel injector 6 circuit poor electrical connection, Ignition coil 6 harness is open or shorted, Ignition coil 6 circuit poor electrical connection, Insufficient cylinder 6 compression, Incorrect fuel pressure, Intake air leak...The P0306 code means that the cylinder 6 is misfiring or is randomly misfiring. Start by checking for intake leaks an if no leaks are found the next step is to replace the spark plugs on cylinder 6. If the problem persist more tests needs to be done to diagnose problem.
first check the output of the exhaust thru the cat,converter. maybe you can even do this with your hand feeling the exhaust flow out of the tail pipe...low/weak/slow?
Kelly it's medium
How many miles on it and when were the spark plugs and coils last changed?
87,431 and with the spark plugs and coils i dont no i just purchase the car bob
Marcus..can you take it to a muffler shop..they can check it for free...
Looking for a Used Grand Marquis in your area?
CarGurus has 8 nationwide Grand Marquis listings and the tools to find you a great deal.
Search Mercury Grand Marquis Questions
Mercury Grand Marquis Experts
Related Models For Sale
Used Cars For Sale