$250 for a hunk of rubber!?!

[06T200]

I don't see how a bad intake tube would fry the cat?? A misfire, raw fuel, cranking the engine too long with the fuel pump hot, clogged air filter, bad plug wire, and even bad plugs will fry a cat, but never seen one burn because of dirty air or wrong MAF signal.

[Drake314]

It's unlikely that the broken intake hose caused your cat convertor to go bad. (I've had split intake hoses on most of the Asian cars I've owned and it never caused the cat to fail.) I recently changed the flex pipe on my '09. The cat converter is NOT in the manifold. It is in the first pipe that is farther back, rearward of the flex pipe. But beware - changing the flex pipe is a bitch of a job, because the flange connection of the two pipes becomes galvanized into one solid mass of rust. That means that if your cat is bad, you will need to replace the front flex pipe as well.

When this happens that the flange connection becomes completely rusted what is the best thing to do to be able to disconnect them? I ask this because I may need to change out the oil pan due to a possible leak in the gasket of the oil pan. I also have an 09 aveo and the flange connection that connects the oil pan to the catalytic converter is completely rusted over as well.

[2010AveoLT]

When this happens that the flange connection becomes completely rusted what is the best thing to do to be able to disconnect them? I ask this because I may need to change out the oil pan due to a possible leak in the gasket of the oil pan. I also have an 09 aveo and the flange connection that connects the oil pan to the catalytic converter is completely rusted over as well.

pretty much your best bet is to soak the fasteners in penetrating oil; if that fails, heat from an oxy acetylene torch is your best friend.

[Thymeclock]

I don't see how a bad intake tube would fry the cat?? A misfire, raw fuel, cranking the engine too long with the fuel pump hot, clogged air filter, bad plug wire, and even bad plugs will fry a cat, but never seen one burn because of dirty air or wrong MAF signal.

I agree. It's 'barking up the wrong tree'.

[Thymeclock]

When this happens that the flange connection becomes completely rusted what is the best thing to do to be able to disconnect them? I ask this because I may need to change out the oil pan due to a possible leak in the gasket of the oil pan. I also have an 09 aveo and the flange connection that connects the oil pan to the catalytic converter is completely rusted over as well.

Your statement does not make sense to me. The oil pan is in no way connected to the catalytic converter or the exhaust pipes. You will need to use a hammer and chisel to separate the exhaust pipe flanges after you cut and drill the fastening bolts out of the flanges.

[2010AveoLT]

I agree. It's 'barking up the wrong tree'.

I've concluded that the bad Downstream o2 sensor I had replaced back in July 2014 (it actually manifested itself a year before, but I could not afford the new sensor due to being a broke college student at the time) contributed to the frying of my cat; but now I'm confused on which one is the actual cat: the one in the manifold (the one that is actually monitored by the Oxygen Sensors) or the one further back in the exhaust system.

[2010AveoLT]

Your statement does not make sense to me. The oil pan is in no way connected to the catalytic converter or the exhaust pipes. You will need to use a hammer and chisel to separate the exhaust pipe flanges after you cut and drill the fastening bolts out of the flanges.

Actually, the flex pipe runs right below the oil pan, as shown in the attached picture.



Sent to the Interwebs by a Phone Shaped Apple

[Thymeclock]

I've concluded that the bad Downstream o2 sensor I had replaced back in July 2014 (it actually manifested itself a year before, but I could not afford the new sensor due to being a broke college student at the time) contributed to the frying of my cat; but now I'm confused on which one is the actual cat: the one in the manifold (the one that is actually monitored by the Oxygen Sensors) or the one further back in the exhaust system.

Let's be clear about this: I had to replace the flex pipe with much effort involved, so I know what is there. The cat converter is NOT in the manifold section, which resembles a pot, and is attached by three stud bolts to the flex pipe. The cat is in the first exhaust pipe that extends reward of the flex pipe. If you don't believe me, try changing a flex pipe on this car and see for yourself. My OX sensor wasn't bad, and there was no reason for it to fail. Actually it came loose very easily compared to all the other exhaust parts. But if you F-ed around with your ox sensor or didn't install it correctly, that might have contributed to your problem.

[2010AveoLT]

Let's be clear about this: I had to replace the flex pipe with much effort involved, so I know what is there. The cat converter is NOT in the manifold section, which resembles a pot, and is attached by three stud bolts to the flex pipe. The cat is in the first exhaust pipe that extends reward of the flex pipe. If you don't believe me, try changing a flex pipe on this car and see for yourself. My OX sensor wasn't bad, and there was no reason for it to fail. Actually it came loose very easily compared to all the other exhaust parts. But if you F-ed around with your ox sensor or didn't install it correctly, that might have contributed to your problem.

but that's the thing: I DID NOT Install it myself: I had my Local GM Dealer install it.

[Thymeclock]

but that's the thing: I DID NOT Install it myself: I had my Local GM Dealer install it.

OK.Then you need to take it up with the dealer. But if they fooled you the first time around, it will be even harder for you to present your case against them and prove it the second time around.