Audi A4 B5 2.8 V6 quattro - CATALYTIC CONVERTERS

[Res1stance]

Hello all,

I'm having an issue that someone here may be able to help me with.
I own a B5 2.8 V6 quattro with 165.000km and days ago I had a CEL with the code p1177. The catalytic converters on my car are still the factory ones, and I believe they're toast although I don't hear much rattling as I read complaints before from other Audi users. However the computer is throwing this p1177. One thing is sure, my flex joints are practically gone, and it may be starting a leak.
My question is, if I install aftermarket catalytic converters, which in this case will be from the brand BOSAL EXHAUST, will my computer throw any CEL's? Can it recognize that these aren't the actual ones from the manufacturer? Must I go with the Audi OEM's?
Also, I'm changing my clutch soon and therefore I must move the down pipes. To do so, I can't imagine these would come off intact, and this BOSAL catalytic converter kit comes with the down pipes as well and flex joints at $518 per side, which is quite cheap.

Any input will be appreciated. Thanks. I just don't want to spend all this money and work and still have a CEL on.

[Res1stance]

Here's the link to the Catalytic converters from BOSAL I mentioned:

http://www.gtaautoparts.ca/ShopByVeh...agrams&mode=PA

[Corrado_Guy]

They should be fine although they typically tend to die faster than the stock ones but they flow much better. If the flex joints are before the cats (I know the V6 A4 exists and little else about this model) then the secondary O2 sensors are behind them and this will cause a cel if they leak and the O2 sensor(s) can be fine. Check the flex joints for leaks and if they do leak you will need to address this first or you will have a drop and get a cel. Other things can cause this as well but if the flex joints are in front of the cats and they are leaking then they will need a replacement,

[NoLag28VAG]

The factory catalytic converters are well made and usually don't bad if your CEL just came on for the code you mentioned. If the CEL has been on for awhile (say 10,000KM or more) then they could actually be bad however there are a few things I will suggest you do before you pony up the coin you are talking about.

I would check the flex pipes for leaks. Most exhaust shops charge about $100 per side to cut and re-weld in new flex pipe sections. Once that is done, run some SeaFoam or some like that to clear some of the carbon deposits that have gotten on the catalysis. See if that solves your issue. If that doesn't do it, you need to change out the four 02 sensors because bank 2 is gone or close to it. You should/would need to change the 02 sensors if you are going to put on new catalytic converters. Changing one O2 sensor is like changing 1 spark plug that has gone bad.

My suggests adds some extra steps but could save you some money if you can resolve it just after the re-weld. If the re-weld does not work, you can always find someone willing to give you a minimum of $100 per side for your cats if the core is not rattling. The OEM has Palladium which is a better catalysis than the Platinum used in the aftermarket units.

[Res1stance]

Thanks for your replies guys! Very appreciated.
When I have the car on the hoist, I can clearly see that all is factory, the flex joints are all buggered although these show no signs of leaks. But if it isn't happening now, it will very shortly as the winters here in Canada are messed up, and therefore there's a lots of salt on the roads. Although I don't hear much of a rattling, I'm the kind of person who prefers to do it right from the start rather than patching stuff.
I was quoted on $200 to just change the flex pipes, but again, the catalytic converters are factory, and these ain't gonna last forever right?! Even if they're not critical now, which I think they are otherwise the CEL wouldn't have come up, they will be shortly by the looks of it.
The code p1177 doesn't refer to a bad o2 sensor, but to the catalytic converters. Since I purchased the car, I had to change 2 o2 sensors already, one in the rear, and another in the front.
I think I'm better off getting the complete system I left the link for, including down pipes as like I said, I'm changing my clutch and the original ones won't come off for sure sure. This way I'll spend all at the same time, but it's the certainty that no problems will occur anytime soon. Would even be a good idea to change the o2 sensor in the back that I haven't changed yet with the whole bundle of work.

Again thanks for your inputs on the matter and happy driving!