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Had the flex part of front pipe spliced in and it only lasted a year. Should I have replaced the whole pipe or is that the life of aftermarket parts.
Usually, extreme short life of a flex pipe means one or more of your engine mounts is broken. Get a helper, pop the hood with clearance in front and in back of the van, STAND TO THE SIDE!!!, have the helper press hard on the brake with the left foot and rev the engine with the right foot in both forward and reverse. Your engine should shift slightly. Any more than slightly or any kind of knock/shift means you've got a broken mount. That said, I often only get 2 years out of a welded-in flex pipe section. The weld tends to create a nexus-point for rust to start and it immediately jumps to eating a hole in the flex section. Northeastern Exhaust/UPSW Auto Parts (same company, I think) sells a complete stainless cat-back exhaust system plus all the pieces separately. They sell on eBay and Amazon, plus through their website and I've had the complete system in my amazon cart for months now, thinking of pulling the trigger. It gets good reviews and it WOULD be nice to not have to worry about the exhaust for 5+ years instead of having to pay a couple hundred bucks every other year at State inspection time plus have a loud van for all the in-between times. The only thing that would give me pause for just the one section is that, if your exhaust is like mine, it has had so many cut/patch jobs done that all the flanges have been replaced by clamped and/or welded sections, so I couldn't just bolt the new section in. However, the cat-back system is under $600.
 

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Discussion Starter · #4 ·
I think it was more of a rust problem that caused the problem. Salty roads in Canada. Hard to protect it from rusting. Maybe there should be a shield on the under side?
 

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I think it was more of a rust problem that caused the problem. Salty roads in Canada. Hard to protect it from rusting. Maybe there should be a shield on the under side?
It IS a rust problem, yes. And one that I know all too well in Southern New England. I get double the salt because I live on an island. But even with rust, the flex should last at least a couple years. Only lasting a year, it typically means rust PLUS excessive movement. You can't use a straight pipe because it NEEDS to flex. Otherwise, you transfer all engine movement directly into the rest of the exhaust. I wouldn't think you could do anything to prevent rust, because of the high temps. One of the big issues with the flex pipe fixes is that they cut out the flex part and weld in a new section. Often, the weld starts rusting almost immediately and then quickly eats into the collar near the top of the woven part, which produces a hole.

Coming at this another way, if you replace the whole pipe section with a Toyota-branded factory original section (P/N:174100A390; $426.45 USD) from the front manifold to the center section, you'll probably get 7 years out of it. If you use an "aluminized steel" (electro-coated with a barely rust-resistant coating) aftermarket exhaust section, you'll probably get 4-5 years out of it. If you clamp in a new stainless section, my guess is that a hole will form just ahead or just behind the clamp section. A stainless exhaust (as I mentioned above) is cheap and easy, if you still have intact flanges in front and behind the flex pipe section. You'll need 3 sets of new hardware and a couple exhaust gaskets. After that, it should last for at least 5 years, unless the actual source of your premature failure IS a broken/worn engine mount or a generally rough-running engine which vibrates more than it should.
 

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Discussion Starter · #8 ·
It IS a rust problem, yes. And one that I know all too well in Southern New England. I get double the salt because I live on an island. But even with rust, the flex should last at least a couple years. Only lasting a year, it typically means rust PLUS excessive movement. You can't use a straight pipe because it NEEDS to flex. Otherwise, you transfer all engine movement directly into the rest of the exhaust. I wouldn't think you could do anything to prevent rust, because of the high temps. One of the big issues with the flex pipe fixes is that they cut out the flex part and weld in a new section. Often, the weld starts rusting almost immediately and then quickly eats into the collar near the top of the woven part, which produces a hole.

Coming at this another way, if you replace the whole pipe section with a Toyota-branded factory original section (P/N:174100A390; $426.45 USD) from the front manifold to the center section, you'll probably get 7 years out of it. If you use an "aluminized steel" (electro-coated with a barely rust-resistant coating) aftermarket exhaust section, you'll probably get 4-5 years out of it. If you clamp in a new stainless section, my guess is that a hole will form just ahead or just behind the clamp section. A stainless exhaust (as I mentioned above) is cheap and easy, if you still have intact flanges in front and behind the flex pipe section. You'll need 3 sets of new hardware and a couple exhaust gaskets. After that, it should last for at least 5 years, unless the actual source of your premature failure IS a broken/worn engine mount or a generally rough-running engine which vibrates more than it should.
Thank you
 
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