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2008 Odyssey Catalytic Converter

8.6K views 26 replies 6 participants last post by  funomance  
#1 · (Edited)
Hi,
My van is just creeping (literally) along. Trying to keep it running til end of year.

Have 220.000 miles on it. Recently did a bandaid fix for a head gasket and was running ok--not using any antifreeze.. Then stopped after driving for half an hour one day to go into a store and came back out, it would not start. Took it to a repair shop and was told the catalytic converter was the problem. Hardly, goes over 40 and 20 or less going up any steep hills. At times seems to have a hard time shifting into the next gear--have no idea what that is about. Also, since this started, my oil light begins blinking after driving for a while. When first start it in the morning, it starts up fine and drives fine for about 5 minutes.

I am going to attempt to take off the second catalytic converter and clean it out--maybe replace it with a piece of flex hose or just leave it out if not too noisy. Is it the second catalytic converter likely the one that is clogged--not the one that comes off the exhaust manifold?

It is getting worse--now gets to where it does not drive over 20 miles an hour. And the engine seemed to overheat because the fan turned on for several minutes after stopping the van. And there is a clicking noise at times from the front of the van. Can a plugged catalytic converter be dragging down the power of the engine to where transmission is not working well and overheating?

Thanks for any thoughts...suggestions...
Darrol
 
#2 ·
This seems likely. If the vehicle cannot breathe than it will create a host of issues. I would definitely take off the cat and see if it's clogged up. These odysseys are pretty notorious for it because of the oil consumption. It will be the third cat under the vehicle not the ones coming off the motor. Take it off and start the vehicle and let it idle. It will be obnoxious but, of it runs steady than you know the issue or once you take it off you can see its clogged. Replaced with another converter not a flex pipe since there is already one on it.

Sent from my SM-N976V using Tapatalk
 
#3 ·
This seems likely. If the vehicle cannot breathe than it will create a host of issues. I would definitely take off the cat and see if it's clogged up. These odysseys are pretty notorious for it because of the oil consumption. It will be the third cat under the vehicle not the ones coming off the motor. Take it off and start the vehicle and let it idle. It will be obnoxious but, of it runs steady than you know the issue or once you take it off you can see its clogged. Replaced with another converter not a flex pipe since there is already one on it.

Sent from my SM-N976V using Tapatalk
Thanks so much, Odyssey Man--like the image
 
#4 ·
What trim level? VCM probably killed your catalytic converter.
 
owns 2006 Honda Odyssey EX
#10 ·
Head gasket failure is extremely uncommon on this engine and is usually caused by some kind of other failure like overheating.

VCM will definitely kill any new catalytic converter you put in. Disable it first.
 
owns 2006 Honda Odyssey EX
#11 ·
Was lining up someone to take the back cat out and see if it is the problem. Talking with a mechanic that works in a Honda repair shop and he said it's the first two cats that go bad first. I was hoping to have this guy work on it but he said did not want to touch it. Anyway, is it likely that the cats up near the engine are bad also? Or they are the ones that are clogging the system up and that I will not likely fix the problem with repairing the second cat?
thanks
 
#12 ·
What can happen is the first catalytic converter near the engine fails, and then the second catalytic converter gets clogged up with the remains of the first one.
 
owns 2006 Honda Odyssey EX
#15 ·
Probably filled with remains from the front cat.
 
owns 2006 Honda Odyssey EX
#16 ·
I went thru this problem a few months back. I just gutted all my cats since they were all clogged anyway. Are you experiencing any smoking? What about a foul smell? I’m having both. I think the cats were hot enough to burn the oil on the way out, but not now.

Also are you getting a CEL light?
 
#17 ·
I went thru this problem a few months back. I just gutted all my cats since they were all clogged anyway. Are you experiencing any smoking? What about a foul smell? I’m having both. I think the cats were hot enough to burn the oil on the way out, but not now.

Also are you getting a CEL light?
Yes, I am still getting a CEL but had that before the cat got clogged because of a head gasket leak.

However, I think I fixed the head gasket leak for a while--it is not using any coolant or very little. But after getting the cat replaced with a pipe I soon started blowing smoke and using oil. From comments above, it sounds like my piston rings were also likely to go bad and it seems they have--or some of them. A mechanic recommended using Blue Devil Stop Smoke along with Prolong Engine Treatment.
 
#18 ·
Since you think it was the rings did you ever run it to like 3k rpms and notice a difference in the smoke? Mine stops smoking altogether if i rev it up. Which makes me thinks its the vacuum system or valve stem seals, but i can’t figure out which.

I wonder what the correlation to using oil without the cats is.
 
#21 ·
The only way to disable the VCM is to purchase an aftermarket VCM Muzzler device, such as the VCMuzzler or VCM Tuner II. There are others as well. Easy to install. Costs around $100.
Read through the first parts of this thread:

 
#22 ·
The VCMTuner II has a good install video on YT made by the creator himself.
 
owns 2006 Honda Odyssey EX
#24 ·
The VCM should not engage when the CEL is on. It sounds like there are other things wrong with the engine. I suggest having a trusted independent mechanic look at it to see what can be done to save it.
 
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#26 ·
A blinking CEL is usually indicative of a misfire which isn't exactly good. You'd be correct, assuming of course that VCM isn't the cause of the CEL.
 
owns 2006 Honda Odyssey EX