So the most likely cause is simple
clogged fuel lines or contaminated fuel from sitting for a long time without being run.
Deposits
clog fuel lines and carburetor jets, cause piston rings to stick, and effectively run the engine too lean (hard starting, loss of power, and more).
Not exact matches
For example, pouring injector cleaner into the tank can loosen the dirt inside the tank and
fuel lines and
clog the injectors instead of cleaning them.
To resolve diagnostic trouble code P0089, the mechanic would test the
fuel pressure regulator, check for a
clogged fuel filter or screen, check for restricted
fuel lines, and test
fuel pump output.
Although changing the spark plugs and O2 sensor tend to fix this type of issue, it could also be caused by dirty
fuel filter,
clogged fuel injector
lines, or another electrical gremlin.
There are a few things that may cause this to happen, such as a
clogged fuel filter, a failing
fuel pump, a restricted
fuel line or in some cases, a faulty
fuel pressure sensor.