G'day, My 00' max has a code of catalyst under threshold. Any idea what this is? The original muffler literally fell off a few weeks ago and I replaced it with an HKS rear section from stillen. Anyone else have the same problem

 

Check to make sure that your O2 sensors are still pluged into the exhaust system. Maybe one got yanked out or screwed up when your rear section was ripped off.

How much of the rear section fell off? Do you have a Cali or Fed spec car? (to know how many O2s you should be looking for.)

 

the exhaust just plain rusted through around the flange by the rear. I have already had O2 sensors replaced on my cali car. Dealer said it was not O2 but the new exhaust.

 

I think that is BS. I doubt that a new rear section would have any effect on the cat or a CEL as long as the O2s are installed right.

Maybe take off your cat and look into it to see if it is melted or if there are pieces broken off. Also check your B-Pipe for pieces of cat.

Hell, maybe the CEL is right!!! Time for a new High flow cat

 

I would like to get rid of this hunk o crap, but I put too much $ into it.

 

I hope your not talking about the Max