97maxy

My Flex Pipe is shot again. This is the 2nd one to go bad within a few years. Yet, as I recall the original Flex exhaust pipe lasted far longer.
Before I go ahead and have one installed I'm wondering is there a difference in quality ? Should I request a certain type/company over whatever they would have just used. I just find it hard to understand why the original lasted for so long, while the replacements went much faster.

Thanks....

jholley

iTrader: (13)

I mig welded this onto my SS Warpspeed cat-free y-pipe 6 years ago

https://www.ebay.com/itm/16129735757...84.m1436.l2649

It is a SS double braided flew pipe much stronger than the accordion flex pipes. It can be welded onto the carbon steel OEM y-pipe or a SS aftermarket y-pipe. That flex pipe stayed rust free for 4 years before I ditched the max 2 years ago.

97maxy

Thanks Jholley.

Is it that it is SS that it will last longer ? The ones the shops put in rusted and wore out in no time.

What is it about the ones the shops are using that causes them to not last ?

jholley

iTrader: (13)

SS will far outlast carbon or aluminumized steel exhaust. Your shop probably just welded on cheap carbon steel flex pipes.

KP11520

Most aren't capable of mig welding with the proper wire and gas to have a factory quality joining unfortunately. Stainless to Normal steel usually don't play nice together. Read up, not easy to find a qualified shop that will do it right. SADLY. Every steel flex pipe welded in my Max lasted just about two years and they kept cutting closer to the factory Y-Pipe til there was nothing left. $200+ a pop.

They'll tell you it doesn't matter about the mis match.

RIGHT!

JH had a SS Y-Pipe so that worked (also needed to be done right)

jholley

iTrader: (13)

Welding that SS flex section onto the SS exhaust pipe only required the carbon dioxide\ argon mix. To weld SS onto carbon steel requires helium and is harder to weld. To get to top half of the exhaust facing the body welded I used an angled tip. Without an angled tip you'll need to drop the exhaust after tack welding.

97maxy

Thanks guys that really explains a lot.



Yes, I think you're right, since it only lasted about 2-3 years they probably only used a cheap steel flex pipe. And eat up most of my Y-Pipe and pipe leading to the Cat in the process.



They did the exact same thing to my Maxi, kept cutting closer and closer to the Y pipe, now there isn't much left to work with.
Now that I've read your replies, I'd say they did it purposely to have customers coming back every few years. As well as have to eventually replace the Y-Pipe itself.



Question: What is the Y pipe made of ? If I replaced the Y should/could I replace it with an SS Y-pipe and then have a SS flex welded onto that ? Or does it not matter ?

Also, as I don't have the equipment to do a proper weld can the flex be attached with U Clamps ? Whereas I could just do it myself, bypass the shop and guarantee a quality SS flex pipe ?

I spoke to a 'muffler shop' just to get an idea and was told they don't weld. What they use is a Y-pipe and flex pipe already welded together from the factory. This is then clamped in place.

Thanks again.....

KP11520

Magnaflow has SS Y-Pipes as does a few other manufacturers, like AP exhaust. Find the model number that works and shop it on Google.

If you have a Cali emissions, it gets a little more complicated and if you live in NY or Cali, Exponentially worse for options and meeting CARB requirements.

Sadly, the same suck a$$ exhaust shops weld the pipes to the final Cat converter, so you sometimes have to replace that too. Bastids.

I live in NY and it was a NIGHTMARE.

97maxy

KP, you're absolutely right. That's exactly what happened, they welded to the Cat and now I think I'll have to replace that also. That and like the rest of the exhaust it's rusted out and needs to be replaced anyway. (New York weather)

(Edit)

And like yourself I also live in New York.

Thanks...

KP11520

I have a Cali Emissions 99 SE so I don't have the rear O2 sensor. I do have 4 O2 sensors pre and post "Pre Cats".

Sounds like you have a Federal Emissions Max. Hopefully, that will be cheaper to find everything and meet requirements. I went SS and the best quality I could find. Just the parts cost me $1400. Everything past the exhaust manifolds and back to the chrome tailpiece and gaskets, O2 sensors and stainless hardware. OUCH Then another $500 for a trusted shop to remove the old, replace the manifold studs and reinstall everything new. NY SUCKS!

The rear O2 sensor has a plug and it might be as far as the engine compartment between the radiator and engine. Look there for the other two plugs for the front O2 sensors. I bet there's a third. It probably comes with a long cord as that should also be replaced when replacing the O2 sensor. Can't help you with any experience on how that's routed point to point. But I suspect a Lift would be handy! As it would be with the rest of the exhaust re-do.

Use NTK O2 sensors. They are the manufacturer for OEM Nissan. I used this guy for O2 sensors and highly recommend his business. Fast delivery, and GREAT pricing shipped: https://www.ebay.com/str/sparkautoparts

As far as Y-pipe with any appropriate Pre Cats integrated, Rear Cat converter and Cat back exhaust.... Magnaflow SS up front and Walker SS catback for everything else. It's all plug and play for the most part. BUT make sure you get the right part numbers for your Fed Maxima. That's not so clear when looking at the options mix.

Research and look into ALL your options. This isn't easy finding YOUR best combination of quality and value that meets NY State's SUCKY requirements. And then you can always go out of state and have it done. But any problems are more work to have remedied.

Hope this helps!

97maxy

Thanks for all the info KP.

Just got back from the parts store, they don't carry the flange that would attach to the Cat coming from the flex pipe. In other words I have the flex pipe then from there a few inches of straight pipe but no flange at the end to attach to the Cat. The flange was cut off. So it's pipe to pipe, connected with an adapter from the Flex to the Cat.

Where can I find just the flange that would normally be welded to the end of the Flex Pipe that then attaches to the Cat ? Is there a chance there is an after market version available ?

If not then I'd have to get the whole assembly Y-Pipe to Flex. Unfortunately my Max is rusted through (NY weather) and probably won't last long enough to warrant a whole new exhaust. I'm trying to piece it together best I can for as many months as I'll have the car.

Thank you...

KP11520

I feel for ya!

There's NOTHING cheap when doing this right. If the rest of the car is going over the cliff sometime in the near future. Cheap piece it together.

If you can read codes, it will tell you which O2 sensor failed and You can replace that. But after you patch the exhaust if necessary. Use the guy above for quality and Cheap OEM.

Then find an exhaust place that will get you another 2 years for as cheap as they can do patching. Unless you are setup for welding and have a lift to have full access working conditions, DIY piecing doesn't work. After they patch it, your O2 sensor might start reading what's supposed to be there instead of some leaky diluted version of gases. If not, order a new one and then you can pass inspection. It's a BIG job to replace a Y-Pipe after being in the car 22 years. Broken and rusted in studs and so on. But you need that flex pipe addressed. So another 2 year bandaid is in order.

There's a real DIVE type exhaust place near Shea Stadium but all those junk yards. (citifield) If anyone can patch it together, he can.

Then there's American Muffler in Westbury. But that's if you're downstate.

jholley

iTrader: (13)

Warpspeed also sells aluminized y-pipes for $300 total. The flex pipe is SS but the rest is aluminized. It is cat-free so you'll gain ~5HP.

http://www.warpspeedperformance.com/...ust-parts.html

As KP mentioned the y-pipe 6 nuts on the manifold studs might be a pain to remove. Spray rust penetrant on the 6 nuts and 2 upstream O2 senors for days.

A new CAT is cheaper. I installed this walker CAT 6 years before I ditched her and it was still good

https://www.rockauto.com/en/moreinfo...11443&jsn=1032

Check to make sure it will pass NY emissions?

The pipe after the CAT can be replaced with an extended resonator. It has the bung for the down stream O2 sensor

https://www.rockauto.com/en/moreinfo...11443&jsn=1057

Rear Muffler

https://www.rockauto.com/en/moreinfo...=1056&jsn=1056

To remove the downstream O2 sensor you'll need to pop the rubber grommet out of the body using needle nose pliers or a flat screwdriver.

KP11520

Hey JH, you wouldn't believe what NY State did to legal exhaust repairs here. They took the majority of emissions products off the table and there's ZERO messing with anything emissions or O2 sensors. The fine for first offense for repair shops is $10K to not make the customer comply.

97maxy

Yes, I'll try my best to piece it together. The car is just too rusted out at this point to really invest that much into it.

That place by Shea is still there ? I remember that place when I lived down in the city.

Thanks KP

97maxy

Thanks Jholley, I learned a lot from this thread. I'll definitely do things differently with my next car and go with the better quality parts you listed in the links. No more cheap parts the repair shops pawn off on you. I might even invest in some equipment and do it myself. More fun that way...

jholley

iTrader: (13)

If it's too corroded to install new exhaust then search for a used Y-pipe. I just sold my OEM Y-pipe on CLs for $30. It had no leaks with only 80k miles on it before I put on the Warpspeed pipe. You can place an add in the 4th GEN classifieds sections with the title "WTB: Y-pipe".

KP11520

JH has a great idea to look for something used, but in real good shape. Just know you'll have to install it yourself. NY doesn't allow shops to install anything used.

I don't know where in NY you live, but if you aren't setup to do this, maybe you are close to NJ, PA, CT or MA. They are more friendly and way less restricted.

97maxy

Thanks guys, yes used would be a good way to go and will definitely keep the costs down.

I'm upstate near the PA/Jersey borders. I spoke with a mechanic who works here in NY but lives in PA. He found a junker for me in PA. I also spoke with Walker and will be doing a mix of new and used. Just tired of patching, as it never really lasts more than a few weeks/months at best. She's pretty rusted, but these Maxis are built like tanks. It might cost a little more, but not having to patch every other week will be well worth it.

One thing, the mechanic mentioned adding some high temp Permatex sealant to the gaskets. Is this worthwhile or are the gaskets more than enough ?