2009 Odyssey with 3.5 liter V6, 257k miles
Hello Scotty. Thank you for all the help you provide to so many people. Please help me understand one detail about the process you described in the most popular video out there on the subject.
I have tried the treatment. 1 gallon of Lacquer thinner mixed with about 11 gallons of fuel in the tank. Ran the engine at 2500 rpm for 30 minutes on Park, in the garage, with a blower placed in front of the van . I was not sure if that's all I needed to do or if I was also expected to drive the van afterwards until the tank was near empty (120-150 miles). Can you elaborate on that? Is the remaining mix ok to use under normal driving conditions or do I need to use up/ deplete the mix asap?
Thanks
Frenchman
Addendum:
I wanted to try the lacquer thinner treatment because I have two CEL codes: P0420 and P0430. Without clearing the CEL codes, I poured the gallon of lacquer in 11 gallons of fuel. Then I ran the engine for 30 min at 2500 rpm, in my garage. Then and drove, right after the 30 min, for 120 miles, I then reconnected the OBD2 scanner to see if the OBD monitor test
saw any improvements. It seems that the Bank 1 CAT is now well below limits.2.83 V where the limit max is 3.1 V. Before the treatment, I had 3.35 V on the monitor test Bank 2 CAT is still above limit. Before the treatment I saw 3.68 V. After the treatment, it was showing 3.15 V.
Why asking for help? I am going to repeat the treatment as someone on another forum suggested.
I just need to know if it is necessary to to the 120-150 mile drive after doing the in-garage 30 minutes engine run at 2500 rpm. Can I just leave the remaining mixture in the tank, maybe just fill it up tp reduce the lacquer concentration, and drive the van as usual? Thanks
I wanted to try the lacquer thinner treatment because I have two CEL codes: P0420 and P0430
With 250k miles, your cats are probably worn out. I've never seen the lacquer thinner trick work. I don't even understand how it could, since its really volatile and would get burned up
If you plan to keep the car (assuming it's in good shape and has been looked after, though I can't imagine the transmission will last much longer), then just replace the cats.
Also, see our FAQ for information how to deal with these common trouble codes.
It seems that the Bank 1 CAT is now well below limits.2.83 V
What kind of limit? These voltages comes from Oxygen sensors before and after the cats (you didn't mention which). To measure catalytic converter efficiency you need to graph data from both sensors over time.
Anyway, I would use up what's in the tank now before refueling. I wouldn't want it sitting around.
@imperator Ok Thanks for the recommendation to deplete the mix left over ib the fuel tank asap..
You asked where I got the 2.83 V value. It was displayed on the OBD2 scanner, monitor test- CAT bank1. I would post an image to show the scanner screen but I cannot figure out how this site manage attachments.
Anyway, today, after driving shorter trips around town, I still have the check engine light ON related to P0420 and P0430. However, it seems that the OBD monitor test on CAT bank 1 and bank are both ok. I think it says the test needs to be repeated 3 times with OK status before the CEL can turn OFF.
It was displayed on the OBD2 scanner,
I know you got the values are from your scanner. I asked which sensor. Like I said, each bank has TWO oxygen sensors. One BEFORE the catalytic converter, and one AFTER. (or upstream and downstream if you prefer). So four oxygen sensors total.
You can't just use static values, because they oscillate. You need to graph them.
This is how you properly diagnose a failed catalytic converter using OBD data.
It's kind of an advanced topic, so probably best left to a competent mechanic who knows how to use the tools (most don't).
I cannot figure out how this site manage attachments.
It doesn't you need to upload them to your own image host. Instructions are on our front page in the Forum Guide.
The vehicle I am dealing with is 2009 Odyssey with 3.5 liter V6. 257k odometer. 2 CATs.
That doesn't answer the question. What is the specific problem? Are you seeing codes or issues in live data?
Are you attempting to "clean" a failing catalytic converter with lacquer thinner? (The limited information given seems to point that way.) That almost never works unless the converter is just barely under the required efficiency specification. There are also other problems that can trigger catalyst efficiency codes, if that's what you're seeing. If your converter is badly contaminated or clogged that stuff will not help, and lacquer thinner is bad for fuel injection components.
I cannot figure out how this site manage attachments.
Possibly you missed the topic "READ THIS FIRST - Forum Guide" posted conspicuously near the top of the main page.