1999 Chrysler Cirrus misfiring

185,978 MILES • 6 CYL • FWD • AUTOMATIC
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USERLIT324
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  • 1 POST
misfiringon 4 and 5 obd readout is po171/po304/po305/po300
Mar 27, 2009 at 10:16 AM
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RASMATAZ
  • ✓Experienced Mechanic
  • 75,992 POSTS
P0171

A lean fuel condition can be caused by:

* Low fuel pressure due to a weak pump or leaky fuel pressure regulator. (use a fuel pressure gauge to check fuel pressure at idle)

* Dirty fuel injectors. (try cleaning the injectors)

* Vacuum leaks at the intake manifold, vacuum hose connections or throttle body. (Use a vacuum gauge to check for low intake vacuum)

* Leaky EGR valve. (Check operation of EGR valve)

* Leaky PCV Valve or hose. (Check valve and hose connections)

* Dirty or defective Mass Airflow Sensor (MAF). (Try cleaning the MAF sensor wires or filament with aerosol electronics cleaner. Do NOT use anything else to clean the sensor, and do not touch the sensor wires)

P0300 Random misfire-normally caused by vacuum leaks and bad fuel.

P0304/P0305-check that cylinder's sparkplug/compression/injector.
Mar 27, 2009 at 10:21 AM
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