Anyone Ever Had This Done?

Hi guys. I took my truck to a well known local mechanic shop with the dreaded P0420 code. The mechanic says he's positive the catalytic converters are bad. He says he can take them off and clean them out and says my truck will be a little louder. I questioned just buying aftermarket converters and my impression is he is just trying to save me some money but I'm not sure this is the best way lol. I'm guessing he has done this before. I'm on the fence having it done this way. Anyone heard of a shop doing converters this way? My truck is 2005 tacoma 2.7L 4 cyl 4wd.

 

There is no cleaning them out, you can knock the guts out of them and put them back on but not only is it illegal for a shop to do that you would still have the p0420 code.
The p0420 doesn't necessarily mean it is plugged, it just means i's no longer functioning like it's supposed to.
Make sure you don't have any exhaust leaks near the downstream O2 sensor as that can cause a catalyst efficiency code to set as well.

 

Thanks for the response. My truck has been running bad for a little bit. No power, bad gas mileage, and sounds like someone dumped marbles somewhere in my exhaust. I would rather buy new converters for it. I think I will think about it before I give them the green light to do it that way.

 

I’ve actually heard of cats being cleaned out. There’s a few YouTube videos about this. The reason cats go bad is the carbon build up inside the honeycomb of internals which reduces their ability to function properly. Ideally you’d want to soak the cats in a detergent that will dissolve/dislodge as much of that build up as possible. Keep in mind that there’s no way to get them back to like-new conditions or get them completely cleaned out but you’d be surprised at how much carbon you can get out of them by soaking and agitating in a dishwashing detergent solution. Dry everything off thoroughly and reinstall.

My disclaimer is that I’ve never tried it myself but the theory is solid. While you’re there you might want to clean off the O2 sensors.

 

Yes, to answer OP’s question. I might be willing to do the soap but dont know about the thinner.

Adding gallon of lacquer thinner per 6-7 gallons of gas is one old trick before removing the cat. After removal, it can be soaked overnight in a laundry soap solution.
https://www.vehiclehistory.com/articles/cleaning-a-catalytic-converter-using-lacquer-thinner

https://www.ericthecarguy.com/forums/topic/cleaning-catalytic-converters-with-soap-and-water/

 

down on power and bad mpgs, your rear cat is probably clogged, there was a recall for this i believe on the 2.7s

 

For me this noise is a dead giveaway that the cat "core dumped". Believe it or not it happened to me 3 times although never heard of it with a OEM unit. The low cost replacement units almost always eventually do this. By core dump I mean the core came loose in the housing. Then obviously it won't function properly and it rattles around in the housing, especially noticeable on decel on mine. You might be able to verify this by hitting the cat with a rubber mallet and you will hear it rattle.

And I don't think you can get a quality cat for less than $800 or so. My OEM was stolen 10 years ago and the muffler shops installed low cost units twice, both failed within 1-4 years. I then installed a Flowmaster myself which had a 5 year warranty and it lasted 6 years. Obviously I could have just purchased a OEM from the beginning and saved a lot of aggravation.

So don't make the same mistake as me, buy OEM or near OEM.