It starts then it stalls, sometimes it starts right up some times it doesn

It could be the Crankshaft Position Sensor - My 1993 Bonneville with a 3.8 had the same issue, I replaced that and it works great now.
It had codes:
17, and 18 I think, or maybe 19 stored. Which was Cam Position sensor, and Crank position sensor problem.
The crankshaft position sensor is easy to replace, if you have access to a pulley puller, some tools and a jack or lift. Some motors need a special tool for an adjustable thing, but most dont have that anymore as I think they recalled it and replaced it on all.
I think they run about 30-60 for a new one, and takes about an hour to replace.
If it is intermittent start problem that may be it. Mine would start fine for a while, then sometimes after Id turn it off, it would just crank and crank, It would start after waiting about 5-30 mintues, while trying to crank it every couple minutes. When driving down the road, it sometimes would stall when turning or stopping.
Hope this helps - Jarett *mechanic with 14 years of experience