No this not the part number, in fact the number is a s/n number for a Cat 3126 A model of which you
have but has two number relate to a 3126 A model. Do not want to alarm you but the way you are
relaying info., I question what went on. with not starting engine. This Sensor is a pressure sensor
direct off the high pressure oil line from HEUI pump that will give pressure or event code with engine
running. Installing a 10,000 psi pressure gauge into the oil rail where sensor is located. To start
engine pressure needed is 870 psi after start and 3,500 - 4,500 to run. Going back to the event codes
number again 164-00 ( engine runs rough, low power), 164-03 IAP open circuit, run rough, low
power, 164-04 IAP short circuit runs rough, low power, 164-11 Injection Actuation pressure, LOW
POWER, ENGINE SHUT DOWN. Part Number 167-1709. Keep going back on your engine running,
does it run rough after warm up. Did mechanic look at engine from inside your motorhome and
Location in question IAP Sensor connection pig tail etc. I'm asking lots of question, but above info.
If related to your problem as mechanic stated. Last answer to your question if problem has been
repaired with install new sensor no you do not need to reinstall a computer again if sensor was the
problem. Everyone does things different but a trained Cat tech will follow a set floor mat for troubleshooting and this is different approach from your mechanic.
Dave Atherton Retired Cat Mechanic.