Not sure about the P1740, but the P0138 is a bad O2 sensor (the one
AFTER the catalytic converter).  NAPA cost is about $72.00.  Mine was a
pain to remove (1999 Ram 1500).  My 02 sensor socket just wanted to
strip it.  I finally intentionally broke off the sensor to the hex and
used an impact socket and impact wrench.  Came right off.  Used
anti-seize on the replacement.

I had the same thing on my Dodge truck. I took it to The Dodge Dealer in
Quincy, Il. Now, bear in mind, the only problem I had was the light coming
on. Unhooking the battery stopped it for awhile but it kep coming back.

The dealer in Quincy Il, fixed the light problem over a year ago and since
then I have had shifting problems. The dodge dealer in Quincy Il, finally
gave the truck back to me and said they couldn't fix the problem.

It shifts from first to second ok. From seconf to third from 25 to 35 mph
makes a bang. It won't shift into overdrive, 5th, until exactly 52 mph. At
51 mph it downshifts.

My advice. Put tape over the light and forget it. It cost me $3,000 and it
still doesn't shift right.