When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I want to bring community awareness, that low quality high flow cats are bad and most likely will cause engine damage. Most aftermarket ones are metal core catalytic converters. When they fail, small metal pieces will be sucked in to the cylinders (usually on WOT), this is where first damage occurs.
It will scratch cylinder walls, some of the debris will exit trough exhaust valves back to exhaust and some of it will be scraped to oil pan. This is were secondary damage will occur. Leftover pieces will be sucked in throughout oil pump. Again, oil pump will suffer some scoring.
And all destruction don't end there. Right after pump, there is an oil filter, in perfect it should catch all abrasive material. But we all know there are situations when bypass valve is open, so all the garbage travels throughout bearings, crankshaft, camshaft...(did couple oil lab test, iron and aluminum levels were elevated)
Same principle applies to all the CATS, including OEM ones too. But they are more robust, higher quality and usually ceramic core.
Damage can be avoided if CAT is installed further down the line (away from engine), it will take longer time to heat up but it will not cause any damage to the engine if it fails and it will last much longer. In other words abrasive material will not be sucked in by the engine.
I am on second Berk set right now, 45k miles on the car. This was the last i installed. Berk, like majority aftermarket exhaust parts manufacturers uses Magnaflows cores. They are cheap and cheap for a reason, they dont last. Between my Acura and Infiniti, had total of 7 failures!
30k the most I could get from a CAT. Some of them lasted only 10k miles
All my cars were tuned by the pro's, fuel trims were right on target.
My suggestion to all of you, get the test pipes. If you cant live with smell, install CAT further down the line. Also, do not buy used one's on the market, it is a ticking bomb. I have seen some of them being on sale with rattling cores..
Some pics: Vertical lines is the damaged caused by the CAT failure. Vertical lines is the damaged caused by the CAT failure. Vertical lines is the damaged caused by the CAT failure. 45k on the engine, very little carbon buildup 45k on the engine, very little carbon buildup 45k on the engine, very little carbon buildup
Had to open mid pipe to retrieve leftover CAT Had to open mid pipe to retrieve leftover CAT Had to open mid pipe to retrieve leftover CAT Another one bites the dust All these small pieces can be sucked in to the combustion chamber beginning to fail
Cat failed but sensor was still reading "ok", no CEL on Acura More vertical damage lines on Acura engine with Nikasil cylinder bores More vertical damage lines on Acura engine with Nikasil cylinder bores More vertical damage lines on Acura engine with Nikasil cylinder bores Should be high quality stuff. $400 core. Installed it on Acura. Infiniti will be next. Should be high quality stuff. $400 core. Installed it on Acura. Infiniti will be next.
This is extremely interesting. You did a fantastic job at documentation.
My initial thoughts were the Acura's position of the EGR hole could have brought this debris in VS the VQ since the cats are positioned lower on the VQ vs the Acura.
That bore scope shows those scratches and based off on what I've seen come from you, you seem to know your stuff.
I believe that the ingestion of these particles don't happen under normal operation but under clogged operation when the exhaust pressure is doing all it can to exit and it can't efficiently then it can travel back into the cylinder since for a moment there would be more pressure in the exhaust than in the cylinder as these forces are trying to escape. At this point most of these failures would compromise AF/O2 sensors but not all.
I believe in your case this has been failing for some time and you happened to catch it based off on the condition of the cores which means the longer you put the this off the closer you could get to catastrophic damages.
It sucks that so much money spent to trying to obtain power and keep emissions happy would end in such a failure especially after so much money is spent on them.
This is extremely interesting. You did a fantastic job at documentation.
My initial thoughts were the Acura's position of the EGR hole could have brought this debris in VS the VQ since the cats are positioned lower on the VQ vs the Acura.
That bore scope shows those scratches and based off on what I've seen come from you, you seem to know your stuff.
I believe that the ingestion of these particles don't happen under normal operation but under clogged operation when the exhaust pressure is doing all it can to exit and it can't efficiently then it can travel back into the cylinder since for a moment there would be more pressure in the exhaust than in the cylinder as these forces are trying to escape. At this point most of these failures would compromise AF/O2 sensors but not all.
I believe in your case this has been failing for some time and you happened to catch it based off on the condition of the cores which means the longer you put the this off the closer you could get to catastrophic damages.
It sucks that so much money spent to trying to obtain power and keep emissions happy would end in such a failure especially after so much money is spent on them.
EGR valve and cylinder damage is a myth, fake news. This is how misinformation spreads on internet . Let me tell one thing, on transverse mounted engine, first CAT to fail is on BANK 1 due to excessive heat (less cooling). And where do we have EGR valve feed tube? BANK 2!
So it is impossible to teleport debris from from BANK 1 to BANK 2. Also tube located after CAT, debris will follow easiest way out (2.25" exhaust pipe vs 0.75" tube which sits on 90 degree angle. I am not sure how big openings in manifold on older J series engine, but on j37 it is really small. There is no way metal pieces will go through small holes, also those holes are elevated.
Picture of exhaust gas feed holes:
Also on VQ it is hard to tell when cat fails, I did not have lights, rattles. With such a huge restriction I could not feel any power loss. I sent my logs to tuner, because i was suspicious and asked him if he sees anything out of ordinary. His response was log's look great.
I have seen ceramic CATS failures on Hyundai I-4 engines. Damaged was much worse and only about 50% of CAT surface area was compromised. It looked like somebody pored sand in to the cylinders...
Also on VQ it is hard to tell when cat fails, I did not have lights, rattles. With such a huge restriction I could not feel any power loss. I sent my logs to tuner, because i was suspicious and asked him if he sees anything out of ordinary. His response was log's look great.
I have seen ceramic CATS failures on Hyundai I-4 engines. Damaged was much worse and only about 50% of CAT surface area was compromised. It looked like somebody pored sand in to the cylinders...
Care to relay what those suspicions are? It baffles me seeing those pictures and not "feeling" any differences.
I had a similar case on an old accord that would sound like a jet even after a CBE.
This is extremely interesting. You did a fantastic job at documentation.
It certainly is, and he certainly did. It's one of those write ups that is sure to convince people to stay away from aftermarket cats.
However, (because there's always a however), the aftermarket industry for cats is huge, and is always one of the first (second or third) modifications for the average bolt-on car enthusiast. So if this is the first time someone is reading about this, it's probably because the overwhelming majority of aftermarket cats don't suffer this kind of failure, irrespective of how obvious or unfortunately repetitive it was to the OP.
I'm tempted to rename this thread "Why I will never buy another high flow CAT!"
That feels more appropriate. Anyway, sad story, probably good advice, and certainly great documentation.
It certainly is, and he certainly did. It's one of those write ups that is sure to convince people to stay away from aftermarket cats.
However, (because there's always a however), the aftermarket industry for cats is huge, and is always one of the first (second or third) modifications for the average bolt-on car enthusiast. So if this is the first time someone is reading about this, it's probably because the overwhelming majority of aftermarket cats don't suffer this kind of failure, irrespective of how obvious or unfortunately repetitive it was to the OP.
I'm tempted to rename this thread "Why I will never buy another high flow CAT!"
That feels more appropriate. Anyway, sad story, probably good advice, and certainly great documentation.
Reading this thread has put the fear of god into me. This is the first horror story I have read but still makes me hesitant about getting the kinetix or berks HFCs. Any input if this is more an issue with buying cheap ebay ones or is this a serious possibility even with higher end ones. I just don't see the fast intentions, berk, or z1 HFC failing like this. Please correct me if I am wrong bc it will save me time and headache with making my choice of which brand HFC i purchase.
Reading this thread has put the fear of god into me. This is the first horror story I have read but still makes me hesitant about getting the kinetix or berks HFCs. Any input if this is more an issue with buying cheap ebay ones or is this a serious possibility even with higher end ones. I just don't see the fast intentions, berk, or z1 HFC failing like this. Please correct me if I am wrong bc it will save me time and headache with making my choice of which brand HFC i purchase.
Berks and Kinetix used same Magnaflow cores in the past. I like Berks better, they use high quality stainless, have mounting for transmission bracket and also what is very important to me-304 stainless flanges.
Berks and Kinetix used same Magnaflow cores in the past. I like Berks better, they use high quality stainless, have mounting for transmission bracket and also what is very important to me-304 stainless flanges.
Ended up going with the kinetix. Berks definitely seemed like the better choice for long term but would have had to wait.. end goal is to go long tube within the next year. So went a little cheaper since I may only have them only for a year at most. Happy to know that they use the same core though in the past, hopefully that hasn't changed.
Why I will never buy another high flow CAT
. Let me tell one thing, on transverse mounted engine, first CAT to fail is on BANK 1 due to excessive heat (less cooling). And where do we have EGR valve feed tube? BANK 2!
. I'm worrying too because I beat her here and there too, myself.
