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Trying to get this panel off to drop the exhaust The bolts started to come out and got loose, guessing the welded nut came undone, is there a way to access it from the top? Maybe under the seats or the center console? Can’t find a diagram online showing if I can even get to them. The flange is too rusted to get a socket on so I’ve given up on that, don’t want to cut it just yet cause the exhaust is original (310,000 miles!) and not very rusty, and I want to cut on the weld for the CAT which I can’t get unless it’s out. Hopefully somebody has done this before, otherwise I’m gonna start cutting 😂.
Take your converter off and remove the catalyst honeycomb? Magically think you can "clean" a ceramic honeycomb? Why?
im gonna soak it in dish soap and steam it to get all the soot off. It burns oil and the exhaust pushes back into the engine or it’s just too restricted, causing it to drive like a turd, hence the name😅 also my theory is it’s causing it to burn oil because of the back pressure, also have to check the PCV system or maybe it’s the rings seeing as it has 310,000 miles. Im not buying a new one because it’ll just rust off seeing as it won’t have a coating like the original exhaust does. I asked for advice, so it'd be nice to get some rather than just criticizing me, it’s not really helpful, thanks!
Last edited by BigBlueWhale; 01-29-2023 at 07:28 PM.
have you considered cutting or snapping off the bolts to separate the pipes? Not sure which side you are having trouble with - the front side or the bolts between the cat and center section of the exhaust, but once you have the parts out you can always drill out the old and insert a new through bolt (that's what I did when I had to replace my center exhaust section after the flange cracked). If your cat is truly clogged you will likely have to replace the cat which is part of the flex pipe ( not sure what year / model you have but Bosal sells a piece for about $400 or if you have welding skills you may be able to find a generic cat that fits the parts.) My two cents is if you are going to the pain of pulling the cat out, you might as well install a new part . Also plan on replacing the O2 sensors while you are there (Bosch sells generic 4 wires you can slice in to save some $$ vs OEM with the made to fit wire harness. If your car is a turbo and it has a clogged PCV, you may have a vacuum issue which is keeping the boost from coming on so it may not even be the cat. I'd probably suss that out first and also do a compression test (wet/dry) to see if you have serious blow by issues. Not sure if you are trying to pass emissions or even live in a state with an emissions test which is something else to consider.
have you considered cutting or snapping off the bolts to separate the pipes? Not sure which side you are having trouble with - the front side or the bolts between the cat and center section of the exhaust, but once you have the parts out you can always drill out the old and insert a new through bolt (that's what I did when I had to replace my center exhaust section after the flange cracked). If your cat is truly clogged you will likely have to replace the cat which is part of the flex pipe ( not sure what year / model you have but Bosal sells a piece for about $400 or if you have welding skills you may be able to find a generic cat that fits the parts.) My two cents is if you are going to the pain of pulling the cat out, you might as well install a new part . Also plan on replacing the O2 sensors while you are there (Bosch sells generic 4 wires you can slice in to save some $$ vs OEM with the made to fit wire harness. If your car is a turbo and it has a clogged PCV, you may have a vacuum issue which is keeping the boost from coming on so it may not even be the cat. I'd probably suss that out first and also do a compression test (wet/dry) to see if you have serious blow by issues. Not sure if you are trying to pass emissions or even live in a state with an emissions test which is something else to consider.
emissions it’s not a problem any more for me, it just turned 25, it’s a n/a so no turbo problems. im having a problem with the center piece under the exhaust about half way down. Cutting the bolts might work, I’ll just have previously welded nuts flying around😂. I’m definitely doing the o2 sensors, to my knowledge they’ve never been replaced seeing as how stuck they are, but I doubt the originals could last this long. I like the idea of just snapping the flange bolts.The flange is the only rusted part so I might just cut it there and shimmy it out Instead of cutting the pan under it. After this I’m gonna try and do a leak down on it😬. Thanks for all the info!
Last edited by BigBlueWhale; 10-14-2022 at 07:45 PM.
Reason: Said she and it sounded dumb😂
One more question - are you getting any check engine codes?
Yes, P0172 which concerned me but nothing happened, guessing its because the cat is restricted, it comes in and out, usually comes in when the car is warmed up. I’ve also noticed, because it’s a manual, when I first start driving the revs drop rapidly when I push in the clutch and after it warms up they sometimes go up briefly *it’s not just me, I’ve had others test it 😅*and then hover for a second or two. Also P0455 which comes around in the winter and I’m not taking the gas tank out any time soon😂. Same thing happened with my dads v70.
asked for advice, so it'd be nice to get some rather than just criticizing me, it’s not really helpful, thanks!
No criticism here just trying to understand what your goal is. The ceramic honeycomb in a catalytic converter can get clogged, and more commonly they can break apart and prevent the flow of exhaust, making your car feel like you have a potato stuck in the tailpipe.
I've replaced many clogged/damaged converters and have never considered or heard of putting dawn/dish cleaner in one to break up the carbon that has accumulated for the past 310000 miles.
But sure it might be possible to "clean" a converter. The 850 converters are not as simple as a 240,740,940 converter. Pipes are not straight, etc. And 3 way converters have 2 honeycombs in them. If you were to try to "back flush" a converter you would have to go through the NOX section first to get to the CO/HC section which is the part most likely to be clogged.
If you are not subject to emission inspections you can always simply remove the catalyst material to solve the problem. Many times it simply breaks up and blows out the tailpipe with time anyway. I'll leave my comment on replacing O2 sensors on a 310,000 mile Volvo that burns oil silent for now, but it's not something I would agree with.
No criticism here just trying to understand what your goal is. The ceramic honeycomb in a catalytic converter can get clogged, and more commonly they can break apart and prevent the flow of exhaust, making your car feel like you have a potato stuck in the tailpipe.
I've replaced many clogged/damaged converters and have never considered or heard of putting dawn/dish cleaner in one to break up the carbon that has accumulated for the past 310000 miles.
But sure it might be possible to "clean" a converter. The 850 converters are not as simple as a 240,740,940 converter. Pipes are not straight, etc. And 3 way converters have 2 honeycombs in them. If you were to try to "back flush" a converter you would have to go through the NOX section first to get to the CO/HC section which is the part most likely to be clogged.
If you are not subject to emission inspections you can always simply remove the catalyst material to solve the problem. Many times it simply breaks up and blows out the tailpipe with time anyway. I'll leave my comment on replacing O2 sensors on a 310,000 mile Volvo that burns oil silent for now, but it's not something I would agree with.
emissions isn’t a problem anymore, if I can clean it I will, but like you said it might not work, and the o2 sensors I know it’s not really worth it but might as well do it I guess 😅. And I’m doing a leak down soon and I’ll probably do the rings if that’s a problem, not really in the budget for a full rebuild but I do have the budget to freshen it up. And oh yeah it feels like a potato is in there😂, when I step on the gas it lurches and stutters a bit from it. It’s gonna give me whiplash one day😂.
11-21-2021, 02:30 PM
Trying to clean CAT. can’t get exhaust out.
