Bad replacement cat

Tiny
JMCMAHA
  • MEMBER
  • 2009 FORD F-250
  • 5.4L
  • V8
  • 2WD
  • MANUAL
  • 145,000 MILES
About a month ago I had an after market catalytic converter put on my truck. The mechanic said I should have it checked out. It was idling rough. Nine days later, the rattle started again on the passenger side. I took it back to mechanic and he said it was shot again. Can it take less than two weeks for a new catalytic converter to go bad? I live a mile from my work, so it have much of a chance to heat up.
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Tuesday, April 12th, 2016 AT 8:43 AM

21 Replies

Tiny
HMAC300
  • EXPERT
Not usually have it scanned for codes at auto parts then get back to us. It may be something else which I think it is. In meantime, clean throttle plate on both sides and iac hole with choke cleaner and check hoses for a vacuum leak like cracked /broken etc. It may be an air leak for him to think it's a bad converter.
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Tuesday, April 12th, 2016 AT 9:56 AM
Tiny
JMCMAHA
  • MEMBER
My check engine light NEVER came on through all of this.I was told that a code can't be checked without a light on
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Tuesday, April 12th, 2016 AT 10:02 AM
Tiny
JMCMAHA
  • MEMBER
By the way.I put down manual, but is an automatic
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Tuesday, April 12th, 2016 AT 10:05 AM
Tiny
JMCMAHA
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I'm not sure it's an air leak. The passenger side cat rattles clear as day. When it is cool and not running.I bang on the converters with my hand and nothing rattles. There is also a plastic burning smell on the passenger side. Especially when I jump on it a bit.
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Tuesday, April 12th, 2016 AT 10:13 AM
Tiny
HMAC300
  • EXPERT
Check to see if the rivets broke on shield above converter that may be your rattle or any shield under truck on that side. If you didn't have a light then the first converter was ok but if you hit it and it rattled then it wasn't. I doubt that this is a converter I think it would be something else besides if converter was bad meaning not working it would set a code or light would come on.
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Tuesday, April 12th, 2016 AT 10:37 AM
Tiny
JMCMAHA
  • MEMBER
Thanks. If my dash system shows that I have different fuel levels nearly every time I start the truck could it mean that there is a malfunction with the warning lights? The check engine light is not burned out.
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Tuesday, April 12th, 2016 AT 10:50 AM
Tiny
JMCMAHA
  • MEMBER
So before I got the converter replaced I was losing acceleration. By the time I got it into the shop to get it replaced (a week or so after the rattling started) it was barely accelerating and I didn't think I was even going to make it to the mechanic. Now I have the new cat on and it is starting to hesitate ever so slightly. I still have very good acceleration, but. Should I be driving this vehicle at all?
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Tuesday, April 12th, 2016 AT 11:18 AM
Tiny
HMAC300
  • EXPERT
Ya you aren't going to hurt it have it checked for vacuum at intake if 15" or below suspect a clogged exhaust AFTER the converter. That may be where your rattle is, in the muffler not in the cat. The fuel level problem may be a shorted wire leading to sender or a sender no goo.
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Tuesday, April 12th, 2016 AT 12:01 PM
Tiny
JMCMAHA
  • MEMBER
Ok.I already dropped a 1000$ on the cat.I hope that was an issue. I'm being told that plugs need to be replaced and the passenger side cat needs to be cut out and replaced AGAIN
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Tuesday, April 12th, 2016 AT 12:08 PM
Tiny
JMCMAHA
  • MEMBER
Should I go after the mechanic who put the converter on for not making sure that he meant to get it checked out like IMMEDIATELY after he was done replacing the bad cat? I mean he said I should check it out. But for a new cat to fry in less than two weeks doesn't seem right.
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Tuesday, April 12th, 2016 AT 12:46 PM
Tiny
HMAC300
  • EXPERT
Check fuel pressure with a gauge auto parts rent it.
https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator then go to another shop to get another opinion I don't think this guy know what he's talking about with the testing I've sent would rule out an exhaust system or converter especially if he's saying the converter is bad as well as no codes. besides most converters installed are warrantied for at least 5 yrs, sometimes longer. if you choose to go after the guy is up to you but find the problem first or talk to a lawyer.
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Tuesday, April 12th, 2016 AT 12:56 PM
Tiny
JMCMAHA
  • MEMBER
Talked to the mechanic's assistant and he stated that that should not happen with today's after market cats. He told me that they are heavy metal and should not burn out a cat within two weeks. Told me to get it checked and bring it to their shop to take a look at it. This will be the second time I have taken it back
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Tuesday, April 12th, 2016 AT 3:27 PM
Tiny
HMAC300
  • EXPERT
Take this vehicle to another shop other than the one that it was repaired at. Iforgot to send the pics I printed regarding converters. They are warrantied for that your problem should be tested with the information that I sent to you in previous replies. Read this pic. I think you are asking for more trouble if you take this to the same shop. They shouldn't burn out like that . I don't know what else to tell you so I have no other comments or suggestions.
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Tuesday, April 12th, 2016 AT 4:53 PM
Tiny
JMCMAHA
  • MEMBER
Thank you very much. I appreciate your help! One last question. It is an aftermarket. Is the warranty you attached good for aftermarket cats as well? I am taking it to another shop. Thank you!
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Tuesday, April 12th, 2016 AT 5:16 PM
Tiny
CARADIODOC
  • EXPERT
Excuse me for butting in here. What did your mechanic mean by "have it checked out"? The Engine Computer checks the operation of the catalytic converters while you're driving. What is anyone else supposed to check?

I didn't see anything here that points to a catalytic converter problem, at least with the replacement. The only thing that will damage a replacement is running leaded gas through it, and that wouldn't be the mechanic's fault, or driving with too much unburned gas entering the exhaust system, and the Check Engine light would have told you that. That's not the mechanic's fault either. I didn't read anything that is his fault so why are you itching for legal action? It sounds more like you need an engine performance specialist which most mechanics are not.

My main reason for sticking my nose in here after stumbling across this post is to clarify your misunderstanding about the Check Engine light. I read this real often and I think it stems from incorrect training that some mechanics receive or don't receive. Starting with all '96 models, there are well over 2,000 potential diagnostic fault codes that can be set relating to different things the Engine Computer monitors. Only about half of them refer to things that could adversely affect emissions and those are the codes that must turn on the Check Engine light. Any of the other 1,000 codes could be set in memory and never turn that light on. For that reason, the place to start with any engine running problem is by having the fault codes read and recorded. Whether or not the Check Engine light is or was on has nothing to do with it. Way too many car owners AND mechanics incorrectly think the Check Engine light has to be on to check codes.

You can also get an idea of the severity of a fault code by how the light acts. Once the six-second bulb check is done at engine start-up, the least serious problems never turn the light on, period. A very minor emissions-related problem will turn the light on while you're driving, and if it's an intermittent problem that stops acting up, the light will turn off, ... While you're driving. If it's more severe, the light will "latch" on and stay on, even if the problem stops acting up, until you turn the ignition switch off and restart the engine. Then the light will stay off until the problem is detected again. For still more severe problems, the light will be on anytime the engine is running, even if the problem stops acting up. The most serious problems are when the Check Engine light is flashing. That means bail out and head for cover! Well, actually, it means stop the engine as soon as possible because too much raw fuel is going into the exhaust system where it will burn inside the catalytic converter and damage it from overheating. You don't have to stop the engine instantly like when oil pressure is lost, but I wouldn't keep driving for more than 15 - 30 seconds if I could help it.

Also be aware, for future reference, there is always a long list of conditions that must be met for a diagnostic fault code to be set. One of those is certain other codes can't already be set. If a problem is detected for one circuit that is used as a reference for a second circuit, the computer knows it can't rely on the first one to make an accurate comparison, so anything that uses that first circuit with the problem will have some of its tests suspended. That means that while you're driving around with the first problem, (and a lot of people do with the Check Engine light turned and and glaring at them), a second, totally unrelated problem can develop, and you'll never know it since the light is already on, AND the test to detect that second problem is not being run. It isn't until your mechanic fixes the first problem that the tests resume and the second problem gets detected. That resumed test might run for the first time on his test drive or it might run when you're two miles from the shop, then the Check Engine light turns right back on again. Naturally you think the mechanic is incompetent, but in reality, all he had to base his diagnosis and repair estimate on was the one initial fault code. He had no clue there was another problem.

We hate having to tell you more tests, parts, or services are needed as much as you hate being told that, but we have no choice. This is an especially big problem on anti-lock brake systems on GM vehicles, but it happens on every car brand to some extent. This problem has a much greater chance of popping up anytime a computer-related warning light is ignored for a long period of time. That gives the new problem more time to develop.

As long as I'm at it, I must mention to be aware that diagnostic fault codes never ever say to replace a part or that one is bad. The people at many auto parts stores will read fault codes for you for free, but all they know is selling parts. A fault code only indicates the circuit or system that needs further diagnosis, or the unacceptable operating condition. When a part is referenced in a fault code, it is actually the cause of that code about half of the time. When your mechanic diagnosis the cause of the code, you're paying him to determine what caused that code to set. That can include cut and grounded wires, stretched or corroded connector terminals, and mechanical problems related to a sensor, like air gap spacing and things like that. A sensor or other part is the last thing to suspect after everything else is ruled out. Too many people incorrectly think the computer's fault code tells you which part to replace. If it were that simple, you wouldn't need geniuses like HMAC300.
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Tuesday, April 12th, 2016 AT 9:25 PM
Tiny
JMCMAHA
  • MEMBER
Thanks for your reply! The mechanic that replaced the cat is the one that stated "I should have it checked out". He thought that the issue started with my plugs misfiring. I called the mechanic's shop yesterday and talked to the owners assistant. He was very surprised that a cat could go bad unless than two weeks. He stated that new converters have heavy metals in them and should not melt or burn up within 9 days. I don't want to do anything as far as legal action, by any means. I wanted the problem to go away. The check engine light issue. Is how am I supposed to know something is wrong with my cat when I get no warning light. The vehicle went to crap in less than a week before I had the cat replaced. It's not like I was ignoring an issue. Bam. And it was fried. I'm just a little heated that I'm told about getting new plugs and what not checked out AFTER he replaced the cat. Is the cat flooded with fuel when it is park and idling. Because it doesn't make any rattling. Only when I accelerate. Do these after markets have warranties?
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Wednesday, April 13th, 2016 AT 6:36 AM
Tiny
HMAC300
  • EXPERT
The warranty that I posted in the pic is from an aftermarket cat maker. And amen to what cardio doc is saying. That is only one maker others are different but most have a warranty they have to by law. I have nothing else to say.
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Wednesday, April 13th, 2016 AT 9:27 AM
Tiny
JMCMAHA
  • MEMBER
I asked some questions about my cat. I felt it was defective. The part number comes from Davico MFG. I found the part on the website and there is a clearly marked link labeled Technical Advisory Bulletin right next to the picture of the cat. The link stated the following. 2008-10 250-350 5.4&6.8 Engines: Known Early Failure of Catalyst. The link goes on to state that certain operating conditions can cause catalyst substrate to crack or melt. This can cause symptoms including but not limited to AUDIBLE NOISE (my rattling) from the catalyst Y-pipe and or MALFUNCTION INDICATOR LAMP ILLUMINATION (my indicator NEVER came on). The bulletin goes on to state that: The service action in ADDITION to replacement of this converter is a reprogramming of the Powertrain Control Module (PCM). The last sentence is underlined for effect. The guy who replaced my converter told me to have my engine checked AFTER he put in the converter. He never said anything about reprogramming the PCM. I am going to ask for a full refund for parts and labor. My reasoning is if this guy has been in business for 20+ years he should have known about this issue. He is the supposed "expert". (I have been in the concrete business for many years and I don't want to hear anything about him just being a muffler guy. If he is supposed to know something about the specs of a part. He should know it. If I did not properly pour or do anything out of spec for concrete you would be damn sure I would stand behind my work and fix it). My mechanic who verfied that information about the cat also ran a check on my engine (the 2nd one, by the way) He is a certified mechanic and here are his notes: Customer states that he had cat replaced after 9 days of driving the the new ones are rattling and stinking. Inspect checked for codes on initial inspection and found none present. Raised truck and found both converters rattling. It appears that the Front Y pipe was fabricated and suspect universal converters were used (I read this to the guy who replaced and he said there was "no way" he could do this at his shop). Test drove vehicle and found to run well. Cam timing data PIDS did not vary more than 2 degrees. Fuel trims did not exceed +/-3%. Watching cylinder contribution there were no misfires detected (which is what my cat guy told me was the problem.) Suspect cat converters are rattling from catalyst material cracking. We have confirmed the engine is in proper operating condition and suspect this is a defect caused by manufacturer defect. Customer needs to return to installing dealer for warranty. End quote. I am going after the guy for parts and labor. I believe I have a good case of negligence. If I could find this stuff in 5 minutes.I feel that he should stand behind his work, not claim "he didn't know" and give me a full refund. What are your thoughts?
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Monday, April 18th, 2016 AT 10:10 AM
Tiny
HMAC300
  • EXPERT
Call ford and give them your vin number ask if campaign number 10m05 has been done to or go to a Ford dealer. There is a problem with the Y pipe that can crack and rattle your truck may or may not be covered but they can check. The pcm automatically gets reprogramed as well as a new Y pipe. Then go after the guy because if the company that manufactured it says that then there were instructions that came with it to do the same.
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Monday, April 18th, 2016 AT 12:05 PM
Tiny
JMCMAHA
  • MEMBER
Thanks! Sorry man, but are you saying that PCM should always be reprogrammed and the guy just didn't do it?
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Monday, April 18th, 2016 AT 12:09 PM

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