Engine Code 26 & Engine Noise When Starting, 2 Flashes, Pause, 6 Flashes Options

[6GenCircleLghts]

So I just got this engine code today. What would be first priority to fix? 308,000 miles.

Book says:
Diagnosis - The air/fuel ratio is overly rich

Trouble Area:
Injector Circuit
Injector
Air Flow Meter
Cold Start Injector
ECM


As far as this engine noise, it only happens when it's pretty cold outside like low 30's or below.
http://youtu.be/EUxYJywN87k

[stephen_lee]

on a car that uses a MAP sensor, a vacuum leak would not cause a bucking issue.
the bucking is a misfire, either fuel or ignition related. these cars are old, it could be an ecu or wiring problem.. wayy too much to guess over the interwebs,

but from what you have said you replaced and the symptoms id make sure to do the o2 sensor and check out the tps and wiring for that and the map.
check continuity while wiggling the wire harness in all placed between sensor and ecu. pull up the tps test/adjustments part of the manual and do that, then go from there. if all checks out fine, its ecu. good way to know for sure if it IS the ecu (but not a sure fire way of ruling it out, though) is to open it up and look at the capacitors, if theyre leaky or bulging or discolored around the base, its for sure the ecu.