Toyota Land Cruiser 2002 carbon build up

Aa206535
Mon, 24 Jan 2022 20:16:19 +0000
Maintenance/Repairs

Hello. I own a 02 Toyota land cruiser pick-up i use to go off road. I have been having it for 3 years. (6 cylinder petrol) manual transmission.

As soon as i purchased it 3 years ago I replaced the original manifold with an after marker manifold and removed the cat. converter, (muffler is still in place) both O2 sensors also removed. the vehicle was running smooth with no issue or smell and good torque for a solid 3 years.

A couple of months back I have starting having heavy carbon smell from the exhaust especially when i accelerate. the smell usually travel inside the car only when i have the windows down during deceleration. I also have excess black smoke when revving the engine to its limit.

i have done/observed the following:

cleaned fuel injectors.

cleaned the throttle valve and body.

replaced the spark plugs

Oil level is not decreasing (not burning oil)

coolant level not decreasing (no possible head gasket leak)

no rattling noise/loud noise (possibly no exhaust leak but i have not really checked)

the car still have good torque

no rough idle

black soot can be observed in the parking lot floor from the exhaust especially after cold start

Engine oil has some black residue that appeared after cleaning the injectors

the smell is only from the tail pipe, when windows are up no smell. only when windows are down.

Smell appeared suddenly after taking a 1 day tour off road.

Added fuel injector cleaners and many other additives into the gas tank to remove the carbon build up

drove the car at high RPM/speed to blow off the carbon

with all said above the problem still exists, does anyone have any advice

19 posts - 11 participants