Another S/C'd member worried about his AFR

[HTM Yaris]

Back pressure is a good thing . Some not alot . Without Backpressure(BP) there isn't any exhaust gas velocity . If no BP was a good thing all the real race cars would have exhaust gas being released straight from the exhaust port . ( Yes I realize that exhaust pipes also evacuate heat )


Try this , go turn on your garden hose . See how it flows ? To increase the velocity of the flow you can do 2 things 1. increase the volume of water or 2. partially cover the end of the hose with your thumb (creating BP) .