Dealership can’t help, can you? 2011 Regal

[Owenowen]

Backstory... Buick Regal 2.0 Turbo 2011. 110,000 miles. Turbo let loose and this is where the troubles began. Ran like a dime prior. Had a new turbo installed as well as cat converter a few months ago. Car sat for 1 year before being worked on. After work was completed car still had the check engine light. Was throwing 14 codes related the turbo, a map sensor and a crank position sensor code. Replaced the map sensor and was told the only way to get rid of the codes was a new ECU. This is where it gets interesting....computer replaced and nothing changed. Car is running fine at this point just a check engine light. Then start getting a hard start and some stalling through the high end of first and second. Replace the Crankshaft Sensor and relearned. A week later car went to hell. When cold it has a hard start, shifts hard into all gears, rpm gauge cycles then sits on zero, tpms doesn’t read any tire, and stuck in 2nd when moved to drive. At this point a new computer was installed and no changes. Then the battery light started coming on randomly and reading that the alternator was not charging but it is. Backfires, smell of gas is strong. All wiring was checked by 3 ASE mechanics. Now here’s the kicker...learned if I drive it for 10 minutes, kill the car and start it, it runs almost perfect, still has a power lose at this point and some hesitation thru gears but generally runs. All the issues with the gear locking, sensors not working, car starting are gone until the next time I try to start it. Any more suggestions???

 

[MelsRegal]

What are the current codes?
Did anybody carefully look at the fuse box including removing it to look underneath?
The location where it sat for 1 year, could rodents have done unseen damage?

 

[rodslinger]

What the lowest numerical code on the list. Some faults are responsible for others.

Such as low fuel pressure may start with an p0171 system lean bank one. As it leans out you'll get misfires and random p0300 codes. Likely throwing catalyst efficiency codes p0420.

Start with the p0100 codes and see if they can cause faults down the line.