After new battery put in it starts but wouldn't idle at low rpm

[montevale]

I just bought a 2001 Sebring LXI coupe with a manual transmission ,it was working perfect except the battery needed to be replaced.
After the battery got replaced at a commercial battery outfit, (it took about 10 minutes and I watched them doing it) I started the car and when let go of the gas pedal it immediatelly stalled. I started the car again and again and it started perfectly every time and as long as I kept my foot on the pedal it was running, but wouldn't idle. Every time I took my foot off the gas pedal and the rpm wend down it stalled.
When I asked the mechaninc what was the problem, he told me that this is a "Chrysler thing" and the computer will be automatically reset in about 15k... feeling a bit uneasy about the 15k deal I took off stalling at every red light.

After abut 50k I still had the same problem with stalling so I called the mechanic again. This time he put me on hold and then consulted with other "electricians" who told me that I should turn the lock manually 5 times on the passenger side. Then drive another 15k and then the computher will be reset. Indeed this sounded silly and I inquired if he was "for real", after being reassured that this is a genuane technique used by Chrysler to reduce autotheft I performed the ritual and kept driving... well it is now over a 100k and I have turned keys in multiple combinations in every lock in my car including the trunk...

I'm feeling quite puzzled as of why a simple battery change would produce such results. Obvously I'm going to take it to a licenced Chrysler mechanic now, but just in case if someone knows an answer to this predicament would you please comment.
Thank you.

[das2123]

Sounds like it could be a TPS issue to me.