Exhaust Air Flow Issues
I have a 2000 v6 and i was just wondering if anyone knows whether i would need to tune the cars air/fuel ratio if i were to straight pipe it? the only reason I ask is because for fun me and some friends took off the muffler half of the exhaust and just ran it from the cats to nothing so it was exiting under the car, but after driving it for about 15 minutes the check engine light came on and when we read it with our OBD the code read that the car was running too lean. Were thinking its obviously because there was not enough back pressure so there was too much airflow. So would this still happen if i were to leave the cats but replace the muffler with a 3 1/2 inch pipe?