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Cat. converter going bad...


adallak

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For a month or so I have heard that unusual rattle, which I attributed to some lose exhaust parts hitting the body... Wrong! Today I finally looked closely and found out that the sound was coming from the catalitic converter. Hit it a couple of times gently with a piece of 2 x4, but did not hear rattle. Nevertheless, I am sure that's the culprit. On the side note... I have had that back fire at start for more than a year. Could it be associated with a restricted cat? And the main question: how long can I drive like that? Honestly, I am getting tired of my best friend, my 17 years old Seville... I have been dumping lately more and more money and effort to keep it on the road... Probably, it is time to give up and move on.

The saddest thing in life is wasted talent

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The backfire probably cracked the ceramic in your catalytic converter, not the other way around. You can get a new one from Midas or Meineke for under $200. I would recommend that you do so ASAP because the ceramic will fragment and fill up your mufflers if you don't.

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-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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The backfire probably cracked the ceramic in your catalytic converter, not the other way around. You can get a new one from Midas or Meineke for under $200. I would recommend that you do so ASAP because the ceramic will fragment and fill up your mufflers if you don't.

Thanks, Jim. Yes, that's actually what I thought too. Bachkfires are small explosions in a pretty closed system, so say, 500 explosions would eventually break something... I think backfires were originated with excessive fuel from leaking injectors, so the latter are also need to be replaced. Too much!

The saddest thing in life is wasted talent

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Thanks, Jim. Yes, that's actually what I thought too. Bachkfires are small explosions in a pretty closed system, so say, 500 explosions would eventually break something... I think backfires were originated with excessive fuel from leaking injectors, so the latter are also need to be replaced. Too much!

I replaced a leaking injector this past weekend. Got one from www.rockauto.com. It was an EB (I think?) remanufactured part and it was only around forty bucks and included the O rings. The ACDelco new one was a little over a hundred and didn't include the O rings. Seems to be working good so far.

EDIT: Just saw that you have a 4.9, not sure if they use the same parts or not, but if an EB is available for your car it might be a cheaper option.

WARNING: I'm a total car newbie, don't be surprised if I ask a stupid question! Just trying to learn.

Cheers!

5% discount code at RockAuto.com - click here for your discount!

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Thanks, Jim. Yes, that's actually what I thought too. Bachkfires are small explosions in a pretty closed system, so say, 500 explosions would eventually break something... I think backfires were originated with excessive fuel from leaking injectors, so the latter are also need to be replaced. Too much!

I replaced a leaking injector this past weekend. Got one from www.rockauto.com. It was an EB (I think?) remanufactured part and it was only around forty bucks and included the O rings. The ACDelco new one was a little over a hundred and didn't include the O rings. Seems to be working good so far.

EDIT: Just saw that you have a 4.9, not sure if they use the same parts or not, but if an EB is available for your car it might be a cheaper option.

Thanks Lothos. I know where to get injectors for abot $250 a set. yes, I would replace all of them. I just got the point when I really do not know whether I want to keep tha baby alive... Things are falling apart to often.

Is there a way to get the content of the cat. out? I know it is not good for environment, but I do not drive sometimes for weeks, so it is not going to be a lot of hurm...

The saddest thing in life is wasted talent

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Thanks Lothos. I know where to get injectors for abot $250 a set. yes, I would replace all of them. I just got the point when I really do not know whether I want to keep tha baby alive... Things are falling apart to often.

Is there a way to get the content of the cat. out? I know it is not good for environment, but I do not drive sometimes for weeks, so it is not going to be a lot of hurm...

I was on a forum for my Cutlass Supreme when I had one, and for a similar issue they suggested taking off the cat and knocking out the insides of it. They said it would eventually blow out the tailpipe anyways. I read on here that on the Cadillacs you shouldn't do that, it messes up the back pressure or something.

WARNING: I'm a total car newbie, don't be surprised if I ask a stupid question! Just trying to learn.

Cheers!

5% discount code at RockAuto.com - click here for your discount!

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Is there a way to get the content of the cat. out? I know it is not good for environment, but I do not drive sometimes for weeks, so it is not going to be a lot of hurm...

Yes there is a way to get the contents out of the cat. What you have to do is unbolt the flange that is between the CAT and Y pipe. Use a long sharp pointed rod and stick it in the CAT and start hammering away. Once you get it all broken up, use a shop vac to suck up all the honeycomb pieces so it doesn't get stuck in your muffler when you hook everything back up.

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If you have an oxygen sensor on the rear of the cat, it will throw a code when the guts are removed and the Check Engine light will go on. It won't pass emissions inspection. It's also illegal in most states. Your exhaust note will change, and a knowledgeable listener will know what you've done. I can usually tell a car that has its cat removed (or gutted) when it drives past, even if I'm preoccupied with something else and not particularly watching traffic.

The car will need to run a little richer, which the PCM should handle just fine. The torque curve will be moved up in RPM. The cats shipped with Cadillacs don't restrict, so this might not even be noticeable.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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The CAT on my 91 rattled for about a year, it is an annoying noise, once I replaced it the noise was gone.

I think you are correct about the injector leaking, the backfire is probably raw fuel igniting. If you lift the fuel rail and turn the key on to pressurize the rail, you would see which one was leaking.

It does get to a point where too many things go bad, I know what you mean, that happened quickly on my 91 as you know. I probably could have kept it going but aestetically, it looked bad because the cloth top shell exploded off the car at 60 mph and the top looked bad.

You might be able to pick up a fuel rail with the injectors attached inexpensively from a scrap yard, Good Luck with this, Mike

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Jim and Mike, thank you for your input.

Is there a way to put a new cat without welding the latter to the pipe? I see some pictures in my FSM with quillotine clamps, but it is not clear wthether they can seal the new joint (and how?). You know I hate someone else touching my Cadillac, but I cannot weld! :(

Yes, Mike at some point these cars become traps...

The saddest thing in life is wasted talent

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Cars do not need "backpressure" to function properly. That is an important thing for a 2-cycle engine but not for a 4-cycle car engine.

Knocking out the guts of the converter is illegal in ALL states. That said, I doubt you would notice any increase in loudless of the exhaust but the exhaust will tend to stink. Like Jim said, people might know what you've done and if emmission testing is done in your area, you will fail and that could draw some unwanted attention.

You could use a replacement converter with a clamp and use exhaust cement at the joint when you reassemble the pipes. That will assure the joint is sealed.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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Jim and Mike, thank you for your input.

Is there a way to put a new cat without welding the latter to the pipe? I see some pictures in my FSM with quillotine clamps, but it is not clear wthether they can seal the new joint (and how?). You know I hate someone else touching my Cadillac, but I cannot weld! :(

Yes, Mike at some point these cars become traps...

What I did was bolt it on the front, cut it as needed, and had Midas weld the back for $25... Clear it with them before you start the job. You might ask them what they will charge to put one on that YOU buy.

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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I replaced a leaking injector this past weekend. Got one from www.rockauto.com. It was an EB (I think?) remanufactured part and it was only around forty bucks and included the O rings. The ACDelco new one was a little over a hundred and didn't include the O rings. Seems to be working good so far.

EDIT: Just saw that you have a 4.9, not sure if they use the same parts or not, but if an EB is available for your car it might be a cheaper option.

Thanks Lothos. I know where to get injectors for abot $250 a set. yes, I would replace all of them. I just got the point when I really do not know whether I want to keep tha baby alive... Things are falling apart to often.

Is there a way to get the content of the cat. out? I know it is not good for environment, but I do not drive sometimes for weeks, so it is not going to be a lot of hurm...

I just found out last night that my reman fuel injector is leaking. RockAuto was real good about it, and I only spent two minutes on the phone with them before they said they'd send out a new one today. Great customer service and almost unbeatable prices, I'd definitely order from them again.

The set you're getting, is it new?

WARNING: I'm a total car newbie, don't be surprised if I ask a stupid question! Just trying to learn.

Cheers!

5% discount code at RockAuto.com - click here for your discount!

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I replaced a leaking injector this past weekend. Got one from www.rockauto.com. It was an EB (I think?) remanufactured part and it was only around forty bucks and included the O rings. The ACDelco new one was a little over a hundred and didn't include the O rings. Seems to be working good so far.

EDIT: Just saw that you have a 4.9, not sure if they use the same parts or not, but if an EB is available for your car it might be a cheaper option.

Thanks Lothos. I know where to get injectors for abot $250 a set. yes, I would replace all of them. I just got the point when I really do not know whether I want to keep tha baby alive... Things are falling apart to often.

Is there a way to get the content of the cat. out? I know it is not good for environment, but I do not drive sometimes for weeks, so it is not going to be a lot of hurm...

I just found out last night that my reman fuel injector is leaking. RockAuto was real good about it, and I only spent two minutes on the phone with them before they said they'd send out a new one today. Great customer service and almost unbeatable prices, I'd definitely order from them again.

The set you're getting, is it new?

Lothos,

I was told injectors from Crown Vic worked just fine on 4.9 engines. Thre is a company fivemotors or somethinf which sell remanufactured sets of injectors at great prices.

The saddest thing in life is wasted talent

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Jim and Mike, thank you for your input.

Is there a way to put a new cat without welding the latter to the pipe? I see some pictures in my FSM with quillotine clamps, but it is not clear wthether they can seal the new joint (and how?). You know I hate someone else touching my Cadillac, but I cannot weld! :(

Yes, Mike at some point these cars become traps...

What I did was bolt it on the front, cut it as needed, and had Midas weld the back for $25... Clear it with them before you start the job. You might ask them what they will charge to put one on that YOU buy.

Thank you, Mike. I probably should first address the injectors then move to the cat. The good thing to know was that you were able to drive another year with rattling cat. But first I have to decide whether I want to keep my Seville... Thanks again, gents for your advices.

The saddest thing in life is wasted talent

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My neighbor is selling a 92 Eldorado (Burgundy) in good shape if you want I will look into what he wants for it, Mike

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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My neighbor is selling a 92 Eldorado (Burgundy) in good shape if you want I will look into what he wants for it, Mike

Thanks, Mike. If I decide to give up, I will probably be interested in a 2000 plus Eldo. Do not know yet.

The saddest thing in life is wasted talent

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My neighbor is selling a 92 Eldorado (Burgundy) in good shape if you want I will look into what he wants for it, Mike

Thanks, Mike. If I decide to give up, I will probably be interested in a 2000 plus Eldo. Do not know yet.

ok, I am going to ask anyway, if its $500, I might buy it and get rid of this Deville and start looking for an STS, I'll let you know what he is asking just in case

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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My neighbor is selling a 92 Eldorado (Burgundy) in good shape if you want I will look into what he wants for it, Mike

Thanks, Mike. If I decide to give up, I will probably be interested in a 2000 plus Eldo. Do not know yet.

ok, I am going to ask anyway, if its $500, I might buy it and get rid of this Deville and start looking for an STS, I'll let you know what he is asking just in case

Okay Mike. That Eldo is more dependable than your 1996 Deville, that's for sure. I also know you just love 4.9 powertrain! :D

The saddest thing in life is wasted talent

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Yep everything except the water pump :lol:

I like the NS now too

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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I like the NS now too

If I ever get up your way.... I want you to drive my '06 Performance Sedan. :D:D Magnetic Ride, Performance Algorithm shifting, Four Channel StabiliTrac, 18 inch, 50 series tires etc etc etc .... :D:D:D

And while you are having fun, the Air Conditioned seats and massaging lumbar keeps you cool and comfortable. :D:D

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I like the NS now too

If I ever get up your way.... I want you to drive my '06 Performance Sedan. :D:D Magnetic Ride, Performance Algorithm shifting, Four Channel StabiliTrac, 18 inch, 50 series tires etc etc etc .... :D:D:D

And while you are having fun, the Air Conditioned seats and massaging lumbar keeps you cool and comfortable. :D:D

Bruce, is there anything in the TOS about teasing?, Jim is teasing me :wipetears:lol:

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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I also have had excellent results with the rockauto rebuilt injectors. A neighborhood kid was parting out a 95 SLS a couple of years ago. I bought the entire exhaust system for $20. I put the mufflers and tailpipes on my 94 4.9 deville. It looked and sounded great. The Cat was a total bolt on situation. A flange on the inlet and a clamp on the outlet.

I was sick of looking at the cat and gave it to another kid that has been using on a 86 Mustang! Look for a used cat at a salvage yard or find someone parting one out. The early Northstars have only one Oxygen sensor before the cat and should work on your 91 and be a bolt on.

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