You need to perform stationary & driving check.
Connect Your laptop to the truck, and read diagnostic codes.
If it has CAT engine, use CAT ET.
If it has Cummins engine, use Cummins Insite.
If it has Detroit Diesel engine, use DDDL.
If it has MaxxForce engine, use ServiceMaxx (or NEDs).
If it has Paccar MX engine, use JPRO.
Check both ACTIVE & INACTIVE codes, and write them down & inform the customer.
Keep close attention to codes related to:
– VGT
– VGT actuator
– intake manifold pressure or temperature
– fuel pressure
– fuel pump
– injectors
These codes (and many others) can cause low power issues.
Pay close attention for following codes:
– low coolant
– low oil level
– low oil pressure
– excessive engine temperatures
These codes could tell You that You are dealing with poorly maintained truck that could be hiding potential engine issue, or that the engine had been damaged already.
Once You noted the codes, start the engine.
Verify that You don’t have any funny noises when reeving the engine.
Whistling noises could mean that You have INTAKE LEAK or BAD TURBO.
The delete tuning will NOT FIX any issues related to turbo/intake leak/fuel pressure.
Make sure that engine responds well, and that the foot pedal/high idle/cruise/jakes/PTO/fan/manual fan activation are working.
Once the stationary check is done, take the truck for a spin to see how it runs.
While driving it make sure that cruise control, jakes, PTO, fan, manual fan…are working as they should.
Note all issues, strange noises…that You’ve found.
If You have access to a program like JPRO, that will allow You to read all modules (engine, ABS, transmission, body controller…), connect to truck with it.
Read all fault codes in all modules, and save report.
Engine tuning can not effect ABS, transmission…computers.
If there is any chance, You should remove intake from turbo & check for:
– carbon build up (I recommend cleaning this after the delete)
– verify that turbo moves freely
– verify that turbo doesn’t have excessive play (excessive play means the turbo is probably bad)
– excessive oil in intake (sign of a bad turbo)
It is a good thing to perform intake pressure test.
Inform the owner of the turck about Your findings.
Even though there are a lot of honest clients, there are some who will try to hide a problem, and later try to blame it on You – since You were the last person who touched it.
With this check up, Your job is to find those hidden problems before we do anything, and notify the client.