Replacing the battery would have wiped the Keep-Alive Memory due to the 15 minutes or so that the car was without power, so re-learning the operating parameters afterwards probably helped your Corsica to get its head on straight again.

In the case of this Bonne, though, good grief: The absolute first thing should always be to see what error codes are stored by the SES light, assuming that you have an SES light going in the first place, and practically everything other than sunspots or Rising Tensions in the Middle East will turn on a Check Engine light these days.

I wouldn't bring by bike to "Crappy Tire". I think they hire from the local hostal. Nothing is free from there. They are the home of the $100 oil change. I leaning towards the MAF sensor. Just gotta wait till payday cuz this bonnie is taking more money than the Ex-wife!
I'll keep yah'* posted.

Your car may have a bad coil(*). You can check these by taking the plug wires one at a time off the coils and see if they are firing if not I am willing to bet the farm if you replace a coil or two it will run just fine again. I had to do the same thing to mine and it cleared the backfiring and all right up. Give this a try.

PROBLEM FIXED. *Drum Roll please*.............

HINT* it costs $2.00 fix.
HINT* it is one of the most basic component of basic rountine maintainance.

And the winner is:.......

PCV VALVE!!!!.

Not really me fault though. Turns out the genius mechanic "forget" to put it back in.

OK, so I get to wear the DUNCE hat until I pay off the repairs....lol