Hi everyone. I was on my way to Bentley of Edison yesterday for regular servicing and the check engine light came up. They told me that one of the cats has failed and it would be $15,000 to replace. I need the car to pass emissions soon. Another question is will New Jersey renew my registration if I don’t do emissions? Also what are the effects of the bad catalytic converter? My technician said that the only effect is the engine light and it won’t affect the way the car drives or performs. Is this true? Thank You in advance.

 

Considering that new catalytic converters go for around $1500-2500 each and they can also be replaced by welding in an universal cat at around $500 a pop, someone's a bit ambitious with their pricing and confident that you don't know better. I really hate it when this happens and with a Bentley this seems to happen often. Even when you'll have to go OEM for parts, they're for the most part just really fancy and well-made Volkswagens. There's no added value in a Bentley logo on the cardboard box the parts come in.

 

Thanks for your detailed response. The service advisor told me that the actual catalytic converter itself was about $4,500 or something. But the rest is apparently labor and i find that hard to believe. It will not take over 10 hours to replace the cat. This means they are charging $11,000 in labor! What are my options? How will this bad cat affect my driving, gas mileage, and performance? Please advise.

 

They apparently follow the official instructions to drop the engine. It can be done with the engine in place, there's even a video on YouTube showing how to do it. I'd estimate that changing both cats shouldn't cost more than $1000-1500 in labor and even that might be a bit of a stretch.

I'm not intimately familiar with VAG engine control logic but generally speaking a blown cat shouldn't be a major problem or break anything else. Just annoying because of CEL and error codes. It's a good idea to confirm this from someone who knows this.

 

Thank You. I was a little worried because different resources said different things. Some on google said its going to make the car sluggish, have starting and stalling issues, bad gas mileage, and misfires. My service tech said that the only issue is the CEL but the car should be fine. Say I want to pass emissions, should a catalytic cleaner that I can mix with the fuel work? Or will I be able to get a sports exhaust with cats or something. A little worried about this because I have emissions due in September.

 

Chances are the cat is beyond chemical cleaners. One might be worth a try, it's cheap and can't do any more damage than what's already there. If you've been considering a sports exhaust, this might be the perfect opportunity for a complete, turbo back kit as some of them come with free flowing cats and downpipes. You might also want to have a specialist check why the cat has been damaged - if there's an underlying issue like faulty injectors, fuel pressure problems, ignition coils on their way out or something similar, your new catalytic converter will be very short-lived too.

September is still several months away but it's a good idea to get to the bottom of this pretty soon. It's really annoying when your car doesn't work 100% and procrastinating with repairs doesn't help at all.

 

The advisor said that the cat is bad because of normal usage and just carbon buildup. When you say turbo bad kit, how much can the whole setup be? https://www.mlperformanceusa.com/products/quicksilver-be352s-bentley-flying-spur-w12-and-v8-sport-exhaust

 

Hello @Dgeedhar ,
First we need to know if you have the W12, or the V-8, and exactly which cat is at fault, as even a secondary cat could cause the primary cat to overheat, and eventually fail, which if you continue to drive, will cause catastrophic damage to the engine itself, meaning, turbo damage, valve damage in the heads, or even piston damage, which would lead to cylinder wall damage, so please tell you service advisor to learn more before giving out false information that would cause you excessive damage, let alone the loss of power that will soon follow if indeed either of the 2 or 4 cats are damaged on you vehicle, that is the next item that requires correct information, does you vehicle have secondary cats as shown, or mufflers instead, we all have primary cats.

Next, a scan would be of most help, so that we may have the exact fault code, because without the code, and some proper inspections, we don't know if you have a failing cat, or just a failing O2 sensor.

​​​​​​Sorry @HQL ,
But you will not be welding any $500 off the shelf cats in place of the specially molded primary cats/downpipes of the 2014 FS, not even the 2004-2011 I have seen, it would not be a pretty job, and yes, I recall a video of someone removing the primary cat with the engine transmission package in place, but if I recall correctly, they were only able to access the drivers side, cylinders 7-12 cat, if you have the video, please post it.

Eventhough the 2005 setup that came on my 05 GT, along with the 2011 Supersports engine I installed were the same, meaning, you have the turbo, then the cat, then the downpipe, so in sections, unlike the 2014 FS, that has the the primary cat and downpipe as a one piece unit, and a very distinct design, why do I get the feeling that I already discussed this, I know I spoke on this not to long ago.

I would start by testing the pressure and temperature at each tailpipe, BUT, being that you may have an H pipe in the midsection as shown, I would drop said midsection and the test each downpipe for the same pressure/flow, and temperature, as a clogged/melted/broken in chunks cat will not flow as a good one, you would also want to check downstream through the midsection to be sure not broken pieces of the cat have made it there, therefore clogging downstream sections.

I have given the prices for both engines.

The W12 primaries and secondaries.








The V-8.

 

I have the W12. I have 48,000 miles on it. The car is completely stock. It has everything from factory. They mentioned bank 2 i think and it was a P0420 code(Will call again today to confirm) They told me that the part was about $4,000 and the labor was around $11,000. Say I do a complete cat delete or get QuickSilver BE352S Bentley Flying Spur W12 and V8 - Sport Exhaust(Deletes the secondary cats.) I need some further explanation on the secondary vs primary cats if you don’t mind @Johnny Hotspur GT

 

I only watched the a part of it for reference so if the other side differs this much, I stand corrected. This is the video by Mitsiland Bentley Service, stating 10 hours of labor for replacement. Catalytic converters come in numerous shapes and sizes, not just the common universal "muffler" shape, so choosing the one closest matching the shape, size, inlet and outlet might work. Whether it's feasible compared to a complete replacement unit is debatable, of course.

This is the main reason I recommended consulting someone who knows the specifics of the car model in question.

 

https://quicksilverexhausts.store/collections/bentley-flying-spur/products/flying-spur-w12-and-v8-exhaust-rear-section

This exhaust says it has a secondary cat delete. Do you think this exhaust will work?

 

​​​​@Dgeedhar ,
No, I believe that you are missing the point, the link you have posted, is simply the rear section as quoted, meaning, just the rear mufflers, not the center section, nor the downpipes/cats, the center section with the cats if your 2014 FS has them, is not the issue, the issue lies with the CATS / Downpipes as I showed in the illustration previously posted, items 9 and 10, with part numbers 3W0 253 059 H & J, are you not seeing the pictures posted ?

I seriously can not believe that you went back to BOE after the last fiasco, my offer is still available, I will either drive to you to scan the vehicle, I will take laser point temp readings at each bank exhaust manifolds, each CAT at each Turbo, and then seperate the center section at the flex joints to test the pressure and temp upstream from the H pipe, this will eliminate the question of a failing CAT at each turbo, as the CAT's/downpipes mounted to each turbo, that is where the 4 O2 sensors are located, not the center section cat's.

For reference of removal, as HQ posted, the drivers side cat can be removed with the engine transmission package in place, but, as NOT shown in the video, the passenger side requires dropping the sub-frame completely, and then lowering the engine transmission package a bit to gain access to the passenger side CAT downpipe nuts at the turbo flange, but, it still doesn't equate to 11k for labor, if you have floor jacks and jack stands at home, we can discuss a extremely reasonable transaction for my inspection, steaks, bourbon, scotch, gas money and knowledge fee... 😉

If you are not into dropping 4k+ for each side as per factory oem parts, you could always go the (Big Daddies Garage) route, and or a tuner to eliminate certain emissions ramifications, hint hint...

Johnny

 

Thank you so much for your response Johnny. It seems like you have a lot of knowledge on this issue. I now understand.(I couldn’t see the images you posted previously but now I can). Do you know any place that I can go to that you would recommend and trust? Also since they told me that the car is fine to drive (cats aren’t physically blocked they are degraded) how long do you think I can drive it without any performance/ mpg losses? I also have my emissions in September.

 

@Dgeedhar ,
The whole point is to drop the mid section now, not to drive it at all, drop the mid section now to prove flow, how the *$=> did BOE tell you the cats are degraded, but not blocked, any degrading of said cats, will have a degree of blockage, that is the whole point, if you check engine light is constantly on, even after a scan, and clearing any fault codes, then you have an issue with either CATs, or O2 sensors, so, let me ask, did BOE clear the fault codes and the check engine light was off, but came back on, or has BOE never cleared the fault code, therfore leaving you with the check engine light on all this time ?

If you want to drop the downpipes and clear them, then adding the big daddies pieces, that is up to you, Google big daddies O2, that will get you through you know who, but, depending on your center section being cats, mufflers, of just straight pipes, your exhaust sounds will be considerably louder...

This is my 2011 Supersports engine with the AWE center section and rear mufflers, AWE's rear mufflers are basically straight through, my C/DP's are clear with BD installed.

http://www.bigdaddiesgarage.com/


My GT.


This message will self-destruct in 28 hours.

Johnny

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Thank you Johnny. I don’t know if they have cleared the fault codes. I haven’t gotten the car back as I am getting a window replaced with insurance. So if I purchase this AWE midsection and the big daddies O2 I’ll be fine? Also will this require an engine out?