Hi guys, I’m a horse-owning woman who drives a 6.0L and knows nothing about diesel engines beyond what parts I’ve had repaired or replaced. Thank you in advance for your help and your patience.

Last Wednesday, my truck wouldn’t downshift while accelerating. It would get up to 3000 rpm and the engine would scream, but no downshift. By the time I drove it to the shop in the morning, the problem had gone away. The mechanic checked it out, but couldn’t find anything wrong. On the way home that evening, it started to run rough while idling and would shudder when I accelerate.

Here’s the rundown of recent(ish) maintenance and repairs:
- Oil and fuel filter change about 500 miles ago. Added Archoil 9100 with the oil change and use Archoil fuel additive with most fill-ups.
- High Pressure Oil Pump and 4 injectors replaced last March
- Leece Neville alternator installed about a year ago to replace the DC Power which only lasted two years. Went through 3 Ford alternators before that.
- FICM replaced with a rebuilt one from FICM Repair about 4 years ago
There have been some other repairs in the meantime, but the records are in the truck which I have already dropped off at the shop, so I can’t look them up.

Here are the codes from the ScanGuage II (yes, there are some dupes):
AVG 5.3
CPM 0.328
EGR 23
EOT 123
EOT 87.8
EVD 29
EVM 1
FIP 76
FLP 13.5
FLP 13
FMP 48.5
FSS 420
FVP 13.5
FWT 155
GPH 4.83
HPG 0.9
HPR 82.4
ICP 641
ICP 664
ICV 0.84
ICV 0.86
MAP 12.1
MFD 15
MFD 18.3
SYC 1
TFC 4.02
TFT 143
TFT 110
VFD 7.25
VFD 21.6
VLT 14

Any suggestions on what I should have the mechanic check when he finds my truck in the morning?

Thanks!