Chrysler Repair: 2003 Chrysler Town and Country, chrysler town and country, o2 sensors

Question
I have a code PO 171 System Too Lean (Bank 1).  I have changed both of the  O2 sensors. I reset the codes and the check engine light usually  stays out for about 25 miles. Some times it goes on almost immediately. Do you have any ideas? I would appreciate any help you can give me.

Thank you.

Jim

Answer
Hi Jim,
You could verify the wires going to both sensors are good. The brown/white wires should show 12V when the engine is running or being cranked. The brown/dark green wires should show continuity to pin 27 at the pcm. The black/dark blue wire on the downstream sensor should be continous to any ground point near by on the chassis. The dark blue/yellow on the downstream should show continuity to pin 51 of the pcm. The dark blue/light blue on the upstream sensor should show continuity to pin 30 of the pcm. The brown/light green wire at the upstream sensor should show continuity to pin 18.
None of the last three wires should be shorted to ground when assessed with the plugs being removed from the pcm. If those check out then a problem in the engine may be the issue and we can go from there.
Roland
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Sorry for the delay but I just found your question in the pool.