some procedures I learned from Master Boknoy...

1) remove the air filter and have it washed (pressurized) from the inside, and then... (2)wash your tailpipe (do it at your own risk). the last time our driver did that washing of the tailpipe to our Trooper... our catalytic converter got damaged and replaced right away...

according to Master Boknoy, the first procedure really works.

i dont know about the second procedure...