When they did it they put holes in the casing so there is no back pressure, now my car is idling weird and the computer is compensating so the RPMs go up and down a few 100. Sometimes it will stall out due to the RPMs getting too low. When I am giving it gas it runs fine, but in 5th gear it accelerates slow like its bogged down. Will replacing the converter fix this or is this something else like a throttle control problem?