I got a noticeable performance boost last summer when I did the tuneup and changed out the fuel injectors. I’m wondering if another simple performance boost is available by swapping out the muffler. On the one hand, I don’t notice any weird noises or smells. On visual inspection, to my untrained eye, it all looks “ok” - surface rust but no holes or anything. On the other hand, I got this rig about 7 yrs ago and have driven it over 80,000 miles. It’s the same muffler it came with and I don’t know how old it was then. I also can’t tell what kind it is. It just looks like a rust-colored oval - no logo or anything as far as I can tell.

If I swap it, I’m inclined to go OEM because I’d like it quiet like now, but I’m also open to suggestions because the OEM at Camelback is nearly $500.

Thanks as always for help & advise -


Also, I’m in northern CA on the coast. No snow unless I seek it out, and no salted roads. The vehicle came from Sacramento.

Nope. For starters the exhaust is constricted at the manifold, before the first cat. And tbh replacing a perfectly good OEM muffler with another one will do nothing but waste a perfectly good afternoon

I feel like I am responding to a younger version of me. I had a Toyota with the 3VZ-E engine and I enjoyed tinkering around to make it go faster. It was a successful endeavor, just like your maintenance items are restoring lost power.

Then I bought a 4Runner with the 5VZ-FE. Toyota learned a lot from the design failures of the 3VZ-E that made it so inefficient. The 5VZ-FE, on the other hand, comes pretty efficient as it is from the factory. There a few things you can do for a tiny bit more top end power:

1. Cut into the factory airbox and create a 'power port', also called the 'deckplate mod' on here. It involves installing a 4" deckplate into the front of the airbox behind the headlight. You'll want to get a spare airbox before you do this as modifying the factory air box is not CA smog legal, I failed smog because of it. Thank you @Speedy for continuing to renew your old website: Project SportRunner - Deck Plate Mod

2. Installing an aFe dry filter. They flow better than the OEM paper filters but filter better than the garbage K&N filters you see at the auto parts stores. It compliments the deckplate mod well but holds its own by itself. The deckplate + high flow filter gives the power gains of a full intake system while keeping the intake charge cooler than going with a cone-type intake that sucks in hot air.

The real exhaust restriction is in the downpipe and the catalytic converter like mentioned above. I did have my muffler replaced with a straight-through style Borla muffler but did not notice any performance increase and that was with a supercharger that produces significantly more exhaust gases than a stock engine. Beyond those two items your next step would be to go forced induction with a supercharger kit. But now you are spending $3,800+ and that's a very large jump to make.

Feel free to PM me or check out my build thread for more power adding ideas. Please note that my 4Runner is supercharged, that really does make a big difference.

Supercharge and be done 😎

I kinda agree with @Speedy here. You want more hp. Better off to just super charge it.

Playing with air flow is not going to do much when your exhaust header is restricting you.

Sent from my SM-A505U using Tapatalk

I guess it sorta depends on what you mean by performance boost. You won’t see any horsepower gains but you may make the engine run smoother. Replacing the muffler and doing fresh gaskets all around definitely improved how my engine runs. If you have leaks at the cat or o2 sensors fixing those will certainly help otherwise I doubt you will notice anything

Ok thanks everybody. So regardless of the age and mileage, there’s no need to replace the muffler until it’s having a problem? I mean, it’s not something you just routinely replace every 50,000 miles or something?

I only replace a muffler when it is rusty, damaged or otherwise so ugly I can't stand it. If it has a hole in it or something else that stops it from doing it's job, then I will replace.

So, to answer your question a muffler isn't part of a standard service interval that I'm aware of. Catalytic converters are different (I believe)

Jason

The stock muffler is baffled, which is a series of metal chambers that reduces noise without too much flow restriction. As it's made of stainless steel, it's only weakness is rust and that would be from the outside in. Apart from that (unlikely in CA) it's a non-serviceable part that usually outlasts the vehicle. The only other thing that puts them out of commission is a direct hit from a boulder.

They don't last forever in the rust belt. Lifetime here is 5 to 10 years [15 yeaes at most] None of my 4 runners don't have original tail pipes nor mufflers anymore. They rusted away years ago.

Sent from my SM-A505U using Tapatalk

I mean why would you? It's not a moving part, it's just a metal box. It doesn't wear aside from the elements
At the mileage these rigs are approaching adding a blower can be quite the risky maneuver. Not to mention the price of them...

When they were $3000 I thought it was too much. Now they are even more expensive and used ones aren't much cheaper and often need repairs. I paid a small premium for mine which was already supercharged but nowadays it's getting pricey. It also is frustrating to see M62 superchargers for other makes and models go for $250 or less and a TRD M62 go for 15x the price.

Inflation hitting everything checked M62 price this past week I'm sure all the other tuning stuff has gone up also.
6 yrs ago was $12k to turnkey SC my Audi S5 I passed then I'm sure I'd pass now.

@Langcow1 , check out the Walker Quiet flow SS muffler $140 sound is a tad louder than stock at cold start hi idle and WOT in between it stock sound.
5 yrs on full Walker system been fine.

Muffler doesn't affect performance. I'd be worried about the catalytic converters being clogged. Optimizing air fuel ratio is your goal..