MY GRAND NATIONAL CODE WAS 44 WHAT COULD BE THAT.>?
Oxygen sensor - lean circuit The code 44 for lean exhaust is most likely caused by one or more of the following: 1.) O2 sensor wire - Sensor pigtail may be mispositioned and contacting the exhaust manifold. 2.) Check for an intermittent ground wire between connector and sensor. 3.) Poor ECM to engine block ground. 4.) MAF Sensor - A MAF sensor that causes the ECM to sense a lower than normal airflow will cause the system to go lean. Disconnect the MAF sensor. If the lean condition is gone then replace the MAF sensor. 5.) Vacuum leaks can cause a lean condition and/or possibly a high idle. Check for cracked hoses a bad gasket or a faulty EGR or PCV Valve. 6.) fuel pressure - system will go lean, if pressure is too low. It may be necessary to monitor fuel pressure while driving the car at various road speeds and/or loads to confirm. 7.) Clogged injector or lean injector - perform an injector balance test..
Search Buick Grand National Questions
Buick Grand National Experts