If I leave my catalytic converter alone on my Odyssey...

what problem are you experiencing?

You should be able to find one for much less aftermarket, through a

Why do you think you need one? It could be that one or more of the O2 sensor or the wiring to them is bad & the cat is fine.

To answer your question - if the check-engine light doesn't bother you and you don't have to pass a pollution check, the only impact as far as the car is concerned is that the engine computer will be doing things to the tuning of the engine trying to get in-spec readings from the O2 sensors.

That's what I thought. Yeah, it's the check engine light giving off P0420 reading. I've took it to a shop and they replace dsome engine parts (engine coil, spark plugs, etc.) and the light came back on. So yeah, it could be the O2 sensor or the cat. The car is running fine (so far) so I'm more incline to leave it alone.

If it is either O2 sensor or cat I just wanted to know if there's no potential big damage besides bad fuel economy.

Optimus Prime wrote in news: snipped-for-privacy@4ax.com:

It would be nice if you gve the /year/ of your van...

Aftermarket online will save you money, though the aftermarket cat converter may not last as long. Magnaflow is a popular brand and should run you under $250 at

Catalytic converters tend not to be available at junkyards, due to the precious metals used ones hold.

Are you in California? Like Tegger asked, what year and exact sub- model is your Odyssey?

Thus spake Optimus Prime :

Mileage and exact date of purchase? I could have sworn they had a

Yes, leave it alone and it will come home... wagging its tail behind it.

Optimus Prime wrote in news: snipped-for-privacy@4ax.com:

Cats are 8 years 80K except for a few select CA-market '95, '96 and '97 models. On those, the original cat is warranted for 14 years or 150K miles. (TSB 98-081).

P0420 has just about zero to do with how the engine is performing and almost 100% with how the cat is performing.

There is a TSB out on this specific vehicle (03-073). Basically, the cat is toast and needs to be replaced. Thank your federal government's EPA for that little nugget.

If you are NOT in California, you can get "universal fit" aftermarket cats for about $200 at any muffler place.

If you are 100% certain the MIL illumination only has (and only ever will have) the DTC P0420 behind it, and provided you do not have a regular emissions test in your area, you can safely ignore this DTC and not get the cat replaced. No damage to the engine will ensue.

That's what I want to hear, thanks.

Thus spake Tegger :

Thank you. What I discovered was thie "10/100K" applied to Carol's now sold 96 Accord and was due to a recall campaign. She also got a free service. Recieved the letter 2 weeks after the car was serviced, date limit was like 3 months out. But the dealership, in the interest of contiuned use, refunded the charges.