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Old 04-30-2020, 08:51 PM   #5452
mrg666
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Quote:
Originally Posted by Randoman5 View Post
I'd be interested to see what the actual effect is. I suspect the concern is that it would cause greater exhaust flow to a level that affects air/fuel ratio and causes many minor knock events. Conceivably the computer could be automatically pulling timing out to compensate... But it's also possible I have no idea how the ECU actually works.

It seems like an unnecessary risk with questionable reward.
Knock is less likely after reducing exhaust back pressure by removing the second cat which reduces the cylinder pressure. We are talking about the second cat which has no oxygen sensors. So, AFR is controlled by the oxygen sensors on the first cat which is still there. Second cat shouldn't have much of an effect on AFR. Again, my engine is fine. But you should of course do as you feel less risky. I am just someone on the internet after all.
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