2003 Chevy Malibu car miising under full load

2003 CHEVROLET MALIBU
140,000 MILES • 6 CYL • 2WD • AUTOMATIC
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GEO2
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2003 Malibu 3.1l 6 cylinder. Car misses when accelerating. engine codes thrown are po300 po301... ect. when hooking a computer to the car it shows the timing retarding when accelerating instead of advancing.
Dec 26, 2008 at 4:41 PM
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RASMATAZ
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Random Misfires and at Cylinder no.1

Misfires can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.

Also test the knock sensor-
Dec 26, 2008 at 5:07 PM
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