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Discussion Starter · #1 ·
I have a flex pipe leak and I found a reputable mechanic that has lots of experience with VWs. From reading on here I wanted to get just the flex welded in.


He told me that in the past he has tried welding in flex pipes on VAG cars and that it is not possible to use a short enough pipe as the OEM part.
Further, that using a longer flex pipe mis-calibrates the O2 sensors causing a CEL that is not fixable without properly fixing the exhaust. In fact he showed me one that he had in his shop now due to this issue.

He indicated that he would try welding it in if I wanted, but that he suspected from experience that I would be back a week later with a CEL.
Another local shop initially recommended replacing the entire thing, but then said they would take the exhaust down and weld the flex on and re-install...

Please comment if you have had a flex pipe replacement welded in (I have V6 = not sure if it's the same with 1.8t)
And please comment on whether you have had any issues after replacement.


would like to save the $800 or so that the new OEM part cost with the cats on it.
 

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When I first bought the car (before PW) my flex pipes went. I took it to the dealer, (my dealer is not THAT bad), and they took it to their muffler shop. Dealer claims the muffler shop refused to do it. Apparently the muffler shop said it looked like I drove over something. :S The dealer mechanic took me into the shop under my car and explained the flex pipes and the problem. I ended up having to get two new cats. (V6).

After becoming a member of PW I regret taking it to the dealer instead of looking at other muffler shops and getting another opinion. I could have saved myself a lot of money.

However its been 4 months and I've been CEL free.

EDIT: I reread OP and realized my post is probably useless
 

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I had both flex pipes go on my '00 V6. About three years ago. Took it to a reputable mechanic to cut out the bad flex pipes and weld in new ones. Within a year the flex pipes were gone again with CEL.

Took it to the local muffler shop. They told me that they can't weld new flex pipes, not enough space left or some such thing. Would only do them with a cat change as well for $1200.00 a side.

Did some searching on the internet for a local custom exhaust shop. Found a guy two towns away who does all the fancy exhausts and he took a look at it and said the first guy had used cheap flex pipes and that's why they'd rotted away and second he said he could put new flex pipes in (just took a bit of talent) for $400.00. He also mentioned the O2 sensor issue, in fact my CEL was on when it went in. He did and he showed me his work afterwards, very neat and clean job and no problems since. No CEL in two years. I was told that most people say you have to change the cats because they lack the precise welding technique for cutting the old flex pipes out and fitting new ones in. But it can be done. I'm sure people on here have done it.
 

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Okay.

Let me start with this... my father and I own a VAG specialty shop in RI.

If the cat checks out okay we will remove the exhaust pipe and weld in a flex, whether it be 2.8, 1.8, 2.0, 3.2 etc...

The part about not having a correct size flex is just plain BS!
At the shop we have the bosal catalog.
In that catalog they have the EXACT flex sizes needed to do all of the above engines and they also have a heavier duty inner and outer braid.
I could put the bosal flex next to a oem flex(on the exhaust that is as OE does not sell em seperate) and they would look EXACTLY the same.
Same length same ID, OD everything.

We have done thousands of these repairs.
If done correctly with a GOOD weld and done OFF the vehicle they will last a damn long time.
We have never had one come back for rot or CEL lights(atleast that could be related to the exhaust repair)

If you like I will send you the bosal flex joints for the 2.8.
I guarantee them to be the exact same measurement specs as OEM.

Alternatively I can give you the bosal part number.

The important thing is match the flex correctly.
Do the cutting and welding off the vehicle.
In my experience this is the best way to get a quality weld.


I hope this info helps get the job done the right way.
 

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Resonnatorr is absolutely correct. It can be done and I had two replace on my B5 whei had it. Any good muffler shop can do it. Paid $100 to have both mine welded in...parts were like $50 from exhaustdirect.ca
 

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Discussion Starter · #6 ·
Resonnatorr: :thumbup: :thumbup: Thanks! Exactly what I was looking for. While I think this guy is a good mechanic, I suspect he is not the best welder, so time to find one I guess.

If you could post or send me the Bosal # that would be awesome. It's a B5.5 V6 4motion.


One last thing: How crucial is it to get this fixed quickly? It's been 'loudish' with a CEL for about 2 weeks. I'm replacing the motor mounts early next week, so I'm going to wait at least until then to get it done.
 

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Yeah, *SHOCKING* that some of the OEM parts (such as the flex joints) look exactly like the Bosal units. I'll bet dollars to donuts some of the other exhaust parts look exactly like the Leistritz items, too.

I get a kick out of these dealerships that try to tell you that they're very sorry but these cars are made at a magical workshop where a big elf named St. Vag and his helpers make these cars out of pixie dust.

I mean c'mon. A Vette probably has just as many Bosch sensors and computers as any VAG/Audi.

And as for getting a CEL from a flex joint....it's called a crappy weld with a leak. $7/hour muffler dudes are good for dad's El Camino and that's about it. :p Welding on a flex joint for a qualified muffler dude would probably take less than 20 min. per side with prep once the pipes come off....and most can do it on the car.

AJ


Okay.

Let me start with this... my father and I own a VAG specialty shop in RI.

If the cat checks out okay we will remove the exhaust pipe and weld in a flex, whether it be 2.8, 1.8, 2.0, 3.2 etc...

The part about not having a correct size flex is just plain BS!
At the shop we have the bosal catalog.
In that catalog they have the EXACT flex sizes needed to do all of the above engines and they also have a heavier duty inner and outer braid.
I could put the bosal flex next to a oem flex(on the exhaust that is as OE does not sell em seperate) and they would look EXACTLY the same.
Same length same ID, OD everything.

We have done thousands of these repairs.
If done correctly with a GOOD weld and done OFF the vehicle they will last a damn long time.
We have never had one come back for rot or CEL lights(atleast that could be related to the exhaust repair)

If you like I will send you the bosal flex joints for the 2.8.
I guarantee them to be the exact same measurement specs as OEM.

Alternatively I can give you the bosal part number.

The important thing is match the flex correctly.
Do the cutting and welding off the vehicle.
In my experience this is the best way to get a quality weld.


I hope this info helps get the job done the right way.
 

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Usually they go bad because of a bad mount somewhere or it hit something(snow or ice) I had both mine replaced 3 years ago and never got a CEL. Had my A4 done ..never had a CEL. bring it to someone who knows their sh!t and don't go back to that guy, even if you need air in the tire.
 

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This is a timely post - I just failed inspection due to both flex pipes bad and leaking exhaust. Dealer wants $1,200 per side to replace w/new CAT's (ouch!)
Clock is ticking - I've got 10 days to get the car fixed and bring back to dealer for state inspection. Dealer said to go to a good muffler specialty guy for an estimate to cut out and replace w/new flex pipe sections. He recommended Midas of all places and told me to speak with Mel, a guy that in his opinion is a seasoned muffler repair guy. At this point - this seems like a good option. Mel said he is familiar with and has done a few Audi's of the same vintage which should have the same set up. I am going in for an official estimate on Saturday. Dealer said I should not pay any more than $500 for the job...

I am a bit worried at now learing of the potential CEL issues this may/can cause from this post and the fact that this seems to be a band aid approach to replacing the cats altogether...
Roll the dice - I gotta keep this beastie for another year or two - NO CAR PAYMENTS PLEASE...

Thanks PW!
 

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I don't think it's a band aid at all. The guy I went to said there was absolutely nothing wrong with the cats. That flex pipe can just rust out and apparently can get weakened by the engien's torque. I was very unkoweldgeable about this and basically invited the guy to sell me cats and he said , 100% I don;t need em. As I get it The CEL comes from the o2 sensor near that flex joint being freaked out by the leaking flex joint.
 

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there are a couple of rules that should be in place here.

1.) Every muffler shop that's decent should have a dude named Mel.
B.) 2 welded in flex joints shouldn't cost over a couple hundred with a good shop
III.) VW dealerships should not have, in any way, a service department for use other than as a parts shop.

AJ


He recommended Midas of all places and told me to speak with Mel, a guy that in his opinion is a seasoned muffler repair guy. At this point - this seems like a good option. Mel said he is familiar with and has done a few Audi's of the same vintage which should have the same set up. I am going in for an official estimate on Saturday. Dealer said I should not pay any more than $500 for the job...

I am a bit worried at now learing of the potential CEL issues this may/can cause from this post and the fact that this seems to be a band aid approach to replacing the cats altogether...
Roll the dice - I gotta keep this beastie for another year or two - NO CAR PAYMENTS PLEASE...

Thanks PW!
 

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there are a couple of rules that should be in place here.

1.) Every muffler shop that's decent should have a dude named Mel.
B.) 2 welded in flex joints shouldn't cost over a couple hundred with a good shop
III.) VW dealerships should not have, in any way, a service department for use other than as a parts shop.

AJ
Thanks AJ - I was cracking up @ your #1 - so true about dude named Mel..

I've got a couple of things working against me -
#1 I procrastinated - my car inspection was due Nov 11 - now I'm behind the 8 ball.
#2 I need to get this fixed quickly or dealer will have to re-inspect car for another $70, + I risk getting a ticket for overdue inspection.

I do have a question about the repair - from what I understand they will need to remove the exhaust header to pull the assembly down cut/weld etc.
That is going to run up most of the labor @ Midas $95/hr rate. Parts I think he said the flex joints were around $60 bucks each. So I'm thinking 2-3hours on the headers and an hour for welding should put this around $400. I'll let you guys know on Saturday..

On top of this I found out my gas strut that holds up the hood went out on me. The dealer wants $63 for it.. I saw it online for $44 + $9 shipping. I'm going to see what I can scare up in the used market... Where are all the junkyards? None in philadelphia area that I can see..
 

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185 sounds pretty good ^^.

As for the used parts such as the strut, I'd just do a search for "passat part out" on your local craigslist and see if there's anything. There's always something around here. I'm in need of one wheel. I'd also like to pull the front strut brace from an A6, so I'm going to put a hundy in my pockets (breaking it up into smaller denominations....20 in this pocket, 30 in the other one, etc.) and just go.

Here's a listing in Allentown..Give the guy a call. You can also cross reference the part number from ECS and see if it fits on A4s or A6s (the Passat B5 uses parts from both)...

98 Passat Part out

AJ


Thanks AJ - I was cracking up @ your #1 - so true about dude named Mel..

I've got a couple of things working against me -
#1 I procrastinated - my car inspection was due Nov 11 - now I'm behind the 8 ball.
#2 I need to get this fixed quickly or dealer will have to re-inspect car for another $70, + I risk getting a ticket for overdue inspection.

I do have a question about the repair - from what I understand they will need to remove the exhaust header to pull the assembly down cut/weld etc.
That is going to run up most of the labor @ Midas $95/hr rate. Parts I think he said the flex joints were around $60 bucks each. So I'm thinking 2-3hours on the headers and an hour for welding should put this around $400. I'll let you guys know on Saturday..

On top of this I found out my gas strut that holds up the hood went out on me. The dealer wants $63 for it.. I saw it online for $44 + $9 shipping. I'm going to see what I can scare up in the used market... Where are all the junkyards? None in philadelphia area that I can see..
 

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Im looking foward to the Bosal part # and if possible a good source to purchase it from!
I patched one up hoping it will last till spring.
 

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And as for getting a CEL from a flex joint....it's called a crappy weld with a leak.
Exactly.

As long as nothing is done to kill the CAT (dumping too much unburnt gas or lots of oil into them), the cat should last a long time. The flex joints are the weak link and need replacing more often.
 

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I had both of mine done a year ago. I was left with a solid weld, but an annoying whistle that begins to howl past 2500 rpms.

I've had it looked at by four different shops and nobody can explain the sound. It's not terribly loud but sometimes I feel like these guys:

 

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OK. One of the key rules is to never draw attention to yourself. If you're covered in tattoos the cops can identify you. If your car looks like a x-mas tree with stripes, chromies, tint, stickers, the cops can identify you. If your car is a whistling train, the cops can follow you, then identify you.

This is by far, the stupidest thing I've ever seen. I hope they keep doing it so we can keep identifying the idiots out there. Without this, its a guess, with this there's no doubt who the idiots are. :D

It's just like where I live. No matter what...if there's an issue and the news is gonna interview someone, it will no doubt be the dude in the wife-beater, holding a beer with 3 teeth and a deep southern drawl, or an inner-city idiot with city so deep all the word form one giant syllable caterpillar with no head and no tail.

Excellent find!

AJ
 

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Man some of you are chicken sh!t. this is the first post I have ever seen since I joined about a CEL from flex pipes, yours leak now..got a cel??? oh.
nothing has to come down or out of the car, they simply cut them out, weld them in..that is all there is to it when you have someone who knows what they are doing. If the shop has to order them, leave..they don't do it on a regular basis.
if you do get a CEL it is because you have clean air getting sucked in and the car will most likely run a little rich..throwing a lean code.
 
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