Nothing in the automotive industry is 100%. OBD 11 scanners are as accurate as the computer reads out. The best test for a ctalytic converter is a device that is put in the tail pipe and it measures back pressure and emissions at the end of the exhaust system. The OBD 11 scanner only says that the catalytic converter is not efficient.
The efficiecy is directly linked to engine effiiency including all the computer controls that make the engine run in specs. Changing the O2 sensor is shooting in the dark. An OBD 11 scanner can monitor the voltage swing of the O2 and a mechanic can tell if it is working properly.
Friday, April 14th, 2006 AT 7:16 AM