Help! 370z weird exhaust sounds
 

So recently my exhaust, Tomei catback/Megan Y pipe/Stock cats, has been sounding droney and muffled like it lost power. Car sounds almost farty during warm idle.

It threw code p2a00 and p2a03, wondering what it can be hoping its just an exhaust leak.

Sounds like a leak for sure

my temps have been extremely high. Usually 180-200 average. Lately theyve been 220-250 when I run it hard. Could it be a blocked catalytic ?

How many miles on the cats?

93k miles on the cats

Hm. You're throwing codes for both banks so unless both cats sh*t the litterbox at the same time I don't think it's a blocked kitty. Could be a fuel issue.

Oil temps? If so, that is about normal for a 2012 with stock heat exchanger. Even with an 34 row oil cooler they can get that hot if on track or in the mountains on a curvy road.

Could also be that the AFR sensors in the exhaust track (the first ones) finally gave up. Mine quit around 110k Miles. If you run an OBD2 scanner program, you might see some anomalous readings on the AFR circuits. This is what I noticed and prompted me to replace them both.

Just a thought, but check your exhaust for leaks too.

Correct.

You should be able to monitor your A/Fs to find out if they are operating at all.
Going from a normal sound to a weird sound can be a leak, it can also mean that the cats are done and they messed up the A/Fs as they went.

With the cats clogged the A/Fs will take a beating many times overheating, you can monitor catalytic temp through the A/F sensors.

Any issues with these sensors will usually send the engine into default fuel parameters which mean pig rich airfuels.

I suggest you monitor the A/F readings then take off your exhaust and check those cats.

Once you get the car up in the air you could also check the cats by hitting them with a dead blow hammer and listen for the inside of the cat rattling around as you hit it.

Here are the A/F Sensors readings. Volts are low im assuming? Going to replace both upstream sensors