Hello, my dakota a p0725 code present but it runs fine shifts fine and kicks into overdrive no problems but wont pass emissions. Would love any help! I've changed the crankshaft position sensor because it was running a p0340 code and it would rev by itself to about 1200 rpm and back down randomly and had trouble starting. Since the replacement all those symptoms have vanished but the p0725 code persists. Thanks for any help!

 

What year Dak? Sounds like you need to change the input speed sensor on left side of transmission. Before doing that, check ATF level and clear the code with any code reader. It it comes back, replace with Mopar sensor, not aftermarket. Clear code again before driving.

 

Thanks for the reply, its a 2000 4.7L quad cab sport. sorry to have left that out. The ATF levels are good and the fluid looks to be in good condition. Speedometer works fine on it too which I read is a common symptom with the speed sensor. I've tried to reset the code both by unplugging the batt and with a OBD II scanner and the check engine light comes on instantly on start up for both with the same code..

 

As mentioned,replace sensor with a mopar one an reset /redrive/retest.
These trucks hate aftermarket sensors.

 

sensor did it. driving legal again feels good! thanks everyone