Best wideband placement
I can't see how cats wouldn't effect the readings. To my understanding cats utilize the O2 in order to work. That's part of why we have AIR pumps.
Now, on newer cars I have heard the cats are much more sophisticated. The new cars run a much leaner/efficient mixture, meaning there is not enough o2 in the exhaust gasses to make the new cats work properly (which is why if you just took a brand new cat off a brand new car and stuck in on your car, it probably wouldn't make you pass emissions through the sniffer) The new cats have a reaction that causes Oxygen to be created...or so I have heard.
All in all a perfect world would see us using a stand alone and doing individual cylinder tuning (fuel and spark) for the best possible power. You would treat each cylinder as if it were its own separate motor.
Now, on newer cars I have heard the cats are much more sophisticated. The new cars run a much leaner/efficient mixture, meaning there is not enough o2 in the exhaust gasses to make the new cats work properly (which is why if you just took a brand new cat off a brand new car and stuck in on your car, it probably wouldn't make you pass emissions through the sniffer) The new cats have a reaction that causes Oxygen to be created...or so I have heard.
All in all a perfect world would see us using a stand alone and doing individual cylinder tuning (fuel and spark) for the best possible power. You would treat each cylinder as if it were its own separate motor.
