I have the same code that has come and gone and now is back on my 2002 Caravan. The thing now is that the registration is up for renewal and it won't pass an e-test (I'm pretty sure it won't pass) with this code.

I didn't do anything special other than drive the van last time it went away. If I'm lucky it will clear again and then I can take it for an e-test.

Did the OP finally get his code to clear?

 

I moved your post, Because you were an old post and you may not get much response. The 2002 thru 2005 minivan vans have had some wiring problem at the injector harness. I would start there first. Are you also getting the P0420 code too?

 

http://www.obd-codes.com/p0140 Could be as simple as a downstream O2 sensor change.

 

THanks for the move.

Strangely enough, no P0420 code.

I'll get out my multi-meter and test for heater power and the right impedance. If the wiring seems to be fine I may just try swapping it out - they're only 60$