Question about codes 1211 and 1212 on a 348.

If I am reading the codes correctly I am getting:
1-2-1-1 and 1-2-1-2

My 348 has been in a local shop for ~ 3 months now getting a LOT done, I had it home for a few days. However, on the drive home from the shop I got the above mentioned codes. I took the car back a few days later to have them diagnose / fix the problem.
These codes had appeared before, and were one of the reasons I took the car to the shop in the first place.
I stopped by to check on the progress today and found that they are looking at replacing the "injectors" as part of the problem.

Anyone have any experience with these codes and possible fixes?


Here is a video of one of the codes before I cleared them both:

Ferrari 348ts ECU code - YouTube



Here is a link the the thread I started about the various things being worked on: http://www.ferrarichat.com/forum/348-355/396133-my-348-shop-first-time.html

 

I spoke to the shop owner today and he said they have done all that Ernie mentioned already, additionally they have improved the electrical grounds. They have been speaking to a guy that build the 348 Challenge cars and following his advice.
I was given a detailed explanation of why the injectors were the next problem solving step, but I have to say a good bit of it was over my head.

 

Lated update from the shop manager:

"Long story short, both sides of the engine are lean. We have tried all the suggestions you mentioned as well as several others including making all the grounds better than new. We also increased the duration of injection via the air mass sensor adjustments. The only way we could get the mixture back to reasonable was to increase the fuel pressure."

 

Ernie, thanks so much for all of your input. I got word today that it was finally worked out.
Here is what I copied from the invoice:

check engine lights on.
Discover significant voltage drop in grounds to engine, subframe & coax sheild (ground) for both Oxygen sensors. Fabricate & install grounds for subframe, valve covers & Oxygen sensors. Clean ground & B+ quick disconnects. Ty strap to secure. Remove multiplex connectors from ECU's to check grounds along with idle motors, throttle
potentiometers & air mass meters-OK. Check resistance of air mass meters 395 ohms-OK. Drill & remove AFM adjuster access plugs. Remove fuel injectors & test. Compare to a new injector. All injectors flow within 10% of a new one. Check injector passageways & intake valves -all clean. Reinstall injectors with new seals. Check fuel mixture-still extremely lean. Partially clamp off fuel pressure return lines, mixture comes back in range. After much research, reinstall original fuel pressure regulators, original (1 year only) are 4 bar pressure regulators. Bosch listing & your 348 guide show a 3 bar regulator. Adjust fuel pressure to grossly center fuel mixture in Lambda window (additive & multiplicative values). Adjust throttle plates & linkages.
Discover leaking pulse AIR injection valves & replace. Adjust air mass meters to center additive & multiplicative values. Test drive. Rescan for values. Reinstall plugs for air mass meters. Reininiate control units. Test drive-OK.