Question

2002 Ford Taurus 3.0L won't start P1309 code also P0401, P0402, P0171, and P0172 codes, what is the meaning of the codes?

Answer 1

P0401 Exhaust gas recirculation flow insufficient detected

P0402 Exhaust gas recirculation excessive flow detected.

P0171 Fuel trim lean bank 1

P0172 Fuel trim to rich bank 2

P01309 Misfire

Lets start with the vehicle doesnt start and if it does it runs very poorly,1309 is caused by a camshaft sensor,not synchronizing properly, or a failed camsaft sensor,Do  the cam shaft sensor first clear code and test drive

Becuase you have lean and rich running condition and excessive cranking this would set off  P1309 so would a crank and cam correlations,like a broken harmonic balancer sending wrong timing spark signal,Go to the harmonic balancer see if it shifted to do so you need to remove the drive belt.if the harmonic free spins there would the problem and the solution be at