I am replacing a leaky head gasket and noticed that it looks like a lot of carbon buildup considering that I drive probably 70% freeway miles on the car. 147k miles.
What do you guys think?
This year I replaced the idle air hoses and all rubber vacuum components.
Last year I replaced plugs/cap/rotor on the ignition-side and the o2 sensor.
2 years ago I had the fuel distributor and eha rebuilt and matched and injectors replaced. fuel filter replaced last week (it was a little overdue). Fuel pumps are original. Duty cycle fluctuates around ~48%
I am getting about 20mpg average fuel economy.
Some photos from today:
