scanned my car yesterday and it through 2 codes 44 and 64.
said that the left and right o2's were both running lean. what does this mean.... would i have 2 bad 02's that need to be replaced or could it be a header leak or what? someone please inform me on the possibilities as to what this is!!!


thanks,
-Mike

 

anyone?

 

Typically, that means the O2 sensors are indicating that the mixture is lean, and that the PCM has max'd out the long term fuel corrections (BLM's) and still can't get the A/F where it belongs.

Since you are getting it on both sides, it could well be a problem causing the entire engine to run (true) lean:

-huge vacuum leak, or tear in the intake bellows
-faulty MAF readings, lower than actual
-low fuel pressure.

If you only had it on one side, (false) lean:
-exhaust leak before O2 sensor
-excessive misfires
-faulty O2 sensor.

Of course you might have misfires on both sides, and faulty sensors on both side.

I'd take a look at the BLM's for both sides, and for a wide range of Cells. That would tell you under what conditions the lean condition is occuring.

 

well i have 123,000 miles on the car and have never replaced the 02's.. think this could be the problem? the car was in the shop getting some work done and when they where through with it, it started this. i am thinking maybe they messed up the 02's when they put them back in or something.. think this is a possibility?


thanks,
Mike

 

oh, i forgot to mention, it only happens while i am stopped at a light after sitting for a minute or so or while it is in park for a minute or so. little sluggish when i start to step on the gas..
i was leaning more towards the sensors being bad. my dyno showed my A/F ratio perfect up until 5200-5300 rpm's. thanks for the help