In the past, I have used MMO successfully to clead the top end of my engine (360 MoPar) of carbon, etc. by pouring it slowly down the TBI throat. However, since the bottle does not say anything about using MMO in this way, I was concerned that using large amounts of MMO all at once might damage the CAT, so I would always temporarily take out the CAT and substitute exhaust pipe until all the smoke stopped. My question is this: Can I pour MMO into th engine as described above WITHOUT removing the CAT and still not have to worry about damage to the CAT?