won't stay started on 1998 Ford Escort

ok this is a follow up of my ? that car starts but won't stay started well found out the MAF sensor was bad so got one put in and work on test run n my wife drive 2 work but on her way home started 2 do same as b4 n check 4 code got P0102 MAF circuit low imput n code P0731 but no description on that code so now do I take it back out n have them replace it or could it b something else

1 answer 1 comment
The P0731 = First gear incorrect ratio. Possible transmission problem.
Is the car stalls when you put it in gear, or even in Park?

Zee
it starts but idles rough n backfires or dies but i was wondering i did drive it but it would never get up 2 speed as it only made it to 20 mph n power go up n down so i pull over had 2 b towed home thinking I'll take maf sensor back n have them replace as it is under warranty just seems strange it ran good n test drive n my wife driving 2 work