Originally Posted by 2011 Nismo#91 (Post 1744171)

I know this can and has been an issue for pre-cats. How ever this is just impossible for a normal Cat. Yes there is some gas sucked back during overlap but you have 5 other cylinders one of which will be exhausting completely. So at most the exhaust pressure would be reduced but as for an over all back flow of the exhaust is just BS.

Your blown engine was due to other issues, the destroyed cat is unrelated. And more then likely all the oil burning clogged the cat up and exhaust pressure just ripped through the clog. But all this is difficult to prove hence why they are just replacing the engine.

Originally Posted by Fabsnoop (Post 1737301)

Just went to the dealership to take a look at the broken HFC. The whole entire honey comb of the cat was broken off. It was just moving around freely. The tech at Nissan said "the only reason Nissan decided to replace the motor is because this motor is known for having oil consumption issues." I asked him if he was certain that the cat was the reason the engine failed..He said "it's one of the reasons.." I swear they'll never give you a for sure answer to anything. Should i go the test pipe route, have the hfc replaced (probably the worst idea since permanent viagra), or put the stock cats back on?

Originally Posted by ImportConvert (Post 1745577)

You're lucky he DIDN'T give you a "for sure answer". Shuffle back to the lobby and zip the lip, you just got a free engine even though the crap parts from Berk are what destroyed it. Go play the lotto.

Originally Posted by 2011 Nismo#91 (Post 1744171)

Your blown engine was due to other issues, the destroyed cat is unrelated. And more then likely all the oil burning clogged the cat up and exhaust pressure just ripped through the clog.