EX35 (2009) Exhaust Parts Idiot-Check

[EX-officio]

My '09 EX35 (base) has a mild exhaust leak on the Y-pipe (driver's side) between the engine and catalytic converter.

I'll have help with the actual repair, but I need to buy parts. I'm on a budget but I want to think long-term about this. No other active leaks or rattles, the exhaust is getting some age on it. While I've replaced the radiator and addressed the sunroof leak, I haven't done anything with the exhaust in the 2-3 years I've owned this awesome car.

WHAT IS THE NAME OF THE PIPE?
The crack/leak is on the driver's side portion of the pipe between the engine and the (driver's side) catalytic converter. Is that section of pipe called the "Y-pipe"? Is there a more specific name for that particular section?

BITE BULLET / DO ENTIRE EXHAUST?
Since I plan to keep the car for a while, should I consider replacing the entire exhaust? (I know it's hard to say without seeing it, but the whole exhaust is the same age as the Y-pipe section that has rusted and cracked.)

IF SO, IS THIS WHAT I NEED TO BUY?
To replace the entire exhaust, it appears I need to buy an Exhaust Sub-Muffler Assembly (Part No. 20300-1BA0A) and a Front Exhaust Tube Assembly (Part No. 20020-JL00A ) plus left/right catalytic converters – correct?

WHAT ABOUT A HEAT SHIELD - CRITICAL?
Most of the parts I'm seeing (aftermarket / third-party / eBay / salvage) do not show a heat shield on the "Y" part of the pipe. The guy who's helping me says this should not be an issue. My (original or OEM) exhaust currently DOES have a heat shield. But, I really can't find any options that DO have the heat shield. Is this because it's not a big deal?

SUGGESTIONS FOR MAXIMIZING POWER?
I'm not trying to do some crazy modding, and I don't have the budget for that, but are there any "low hanging fruit" options I should consider when choosing exhaust parts, to maximize airflow/power? I like to get everything I can out of the 3.5 engine. I clean out the air intakes every summer, use the good gas, etc. Interested to know if there's an exhaust kit for, say, a G37 that would fit perfectly and also give a little more oomph without making my O2 sensors have a fit. (I'm not in a state that requires inspections fyi.)

GENERAL RECS FOR WHERE TO BUY
Do people (way smarter than me) suggest avoiding salvage/used exhaust parts as a rule? Are there online options that a noob like me might miss? I've found good options on eBay, FB Marketplace, Giant Exhaust, AHParts, PartsGeek, etc. But I'm the target audience for buying something stupid because I know just enough to forget that I don't know much. Especially about exhaust parts.

Thanks for any input you can share on my stupid-long list of questions.

[VStar650CL]

WHAT IS THE NAME OF THE PIPE?
The crack/leak is on the driver's side portion of the pipe between the engine and the (driver's side) catalytic converter. Is that section of pipe called the "Y-pipe"? Is there a more specific name for that particular section?

It's a Y-pipe. In your case, it also serves as a "flex pipe" because it comprises the flexible couplers which allow the engine to rock. Any other name Nissan may have given it is Japlish.

BITE BULLET / DO ENTIRE EXHAUST?
Since I plan to keep the car for a while, should I consider replacing the entire exhaust? (I know it's hard to say without seeing it, but the whole exhaust is the same age as the Y-pipe section that has rusted and cracked.)

Have an assistant block the tailpipes with shop rags and then listen for other leaks downstream. If you don't find any, don't fix what isn't broke. Modern exhaust systems are all mild stainless steel, so they rust slowly but faster at any busted welds. The flex couplings are also vulnerable because of simple fatigue. It doesn't mean the rest of the system is bad.

IF SO, IS THIS WHAT I NEED TO BUY?
To replace the entire exhaust, it appears I need to buy an Exhaust Sub-Muffler Assembly (Part No. 20300-1BA0A) and a Front Exhaust Tube Assembly (Part No. 20020-JL00A ) plus left/right catalytic converters – correct?

Yes, but refer to the above. Don't replace what doesn't need replacing, very especially the cats. Even on a ride with relatively easy access like an EX, rust will make it a miserable job, and potentially-costly if the wrong things break. Don't do it until the ECM tells you to.

WHAT ABOUT A HEAT SHIELD - CRITICAL?
Most of the parts I'm seeing (aftermarket / third-party / eBay / salvage) do not show a heat shield on the "Y" part of the pipe. The guy who's helping me says this should not be an issue. My (original or OEM) exhaust currently DOES have a heat shield. But, I really can't find any options that DO have the heat shield. Is this because it's not a big deal?

Yes, but the heat shields are clamp-on and you can actually still get those from Infiniti, 20511-JL00A for the lower and 20516-JL00A for the upper. Personally I wouldn't bother.

GENERAL RECS FOR WHERE TO BUY
Do people (way smarter than me) suggest avoiding salvage/used exhaust parts as a rule? Are there online options that a noob like me might miss? I've found good options on eBay, FB Marketplace, Giant Exhaust, AHParts, PartsGeek, etc.

There doesn't seem to be a whole lot out there, but make sure whatever you find is a fit by crossing the original p/n, 20020-JL00A. I strongly recommend new and not junkyard simply because it's a flex pipe. Flexes die from fatigue and not just rust, and if you happen to pull one off a ride which had a bad motor mount, it could break on you tomorrow or a month from now. Not worth the risk.

[EX-officio]

VStar650CL, I don't even know how to express how grateful I was to see this detailed reply. Thank you for addressing all of my questions and giving me such a clear understanding of next steps. Now I have a much better idea of how to proceed.

And thanks for suggesting a way to test the downstream parts that may / may not require replacement. Potentially saving me several hundred dollars on parts that may / may not require replacement right now.

[VStar650CL]