are you sure about the code 89 where do you see this code at? I think you mean P0089.
Error Code P0089: Fuel Pressure Regulator 1 Performance
Error Code P0089 is usually a mechanical fault which, most of the time, can be attributed to the defective electronic fuel pressure regulator or it can be a case of faulty fuel pump. Other most common causes include:
Clogged fuel filter or pinched or restricted fuel lines
Low fuel condition
Faulty fuel pump
Defective fuel rail sensor
Damaged, open or shorted wires (corroded wires)
Damage in electrical connectors
Error on fuel pump output
Qualified mechanics start their diagnosis by hooking up their advanced level scan tool to the PCM. Any error code present will have its own freeze frame data, which includes any info that tells mechanic what circumstances triggered the PCM to set the code. This includes information about the vehicle’s speed, RPM, coolant temperature, etc.
Then, the codes will be cleared and the vehicle will be taken for a test drive.
When the code returns, the mechanic will then conduct a visual inspection of the vehicle and look for signs of damage, restriction or leaks along the fuel lines and fuel pressure regulator.
If all seems well upon visual inspection, the vehicle will now be tested for test port. This is where the mechanic will check the fuel pump output using his scan tool. He will also test the operation of fuel pressure regulator.
How to Fix
The most common fixes for this error code are:
Replace or repairing the damaged or restricted fuel lines
Replace fuel pressure regulator
Replace clogged filters or screens
Replace failed fuel pump