Rep Power: 134

Title says it all. 2005 Civic EX Less Special By The Day Edition, manual transimission, about 190,000 miles.

I put a new downstream O2 sensor in it in early January:

https://www.civicforums.com/forums/3...ml#post4756604

And that's after putting one on back in March of 2018:

https://www.civicforums.com/forums/3...ml#post4742380

They're cheap online, but this is getting to be an expensive habit just the same. Suggestions?

Possibly relatedly, the gas mileage is still kind of lousy. Low 30s for MPG, and it has been even when the MIL has been off.

We *also* have intermittent P1457 and P0497 codes, both of which are EVAP-related. Haven't tried root-causing them because they're intermittent problems. You know, the best kind of problems :-/

Current codes: P0139 and P0497.

 
Rep Power: 222

Did you put in an OEM sensor? Was it from a reputable seller? Sometimes they can be fake, especially if the price seems really cheap

 
Rep Power: 134

I put in a Denso 234-4220 from RockAuto. I assume RockAuto is considered a trustworthy seller of parts who wouldn't have counterfeit stuff?

 
Rep Power: 222

Yeah that shouldn't be the problem then, unless they're getting banged around during shipping. Maybe the connector?

 
Rep Power: 518

if they are only lasting months, buy the right brand/number sensor from local parts store that will give you a free replacement part under warranty every few months

 
Rep Power: 0

Im thinking that two that sensore is probably a cheap knock off use an oem one. & clean the end conector that plugs to the sensore using electrical cleaner spray.

 
Rep Power: 134

That's an interesting idea, but they're ~$220 at a local parts store (both the orange one and the checkered flag one) whereas they're $27 at RockAuto. RockAuto's list of warranties identifies O2 sensors as a wear part and not covered by warranty :-(

Anyhow, it seems fishy that I've had two go bad in a year. Should I be looking for some other root cause to the failures before throwing another part at it?

If it's of any relevance, the LAF I put in almost 4 years ago continues to work just fine, thought I've probably now jinxed it :-(

 
Rep Power: 518

https://www.autozone.com/engine-mana...828034_0_98000

 
Rep Power: 134

I'm sorry if this is a dumb question, but is switching from Denso to NTK recommended?
I've been quoting prices for the Denso part based on the understanding that sensors should be replaced with one matching the original part.

 
Rep Power: 0

If Your spliting hairs between Denso & NTK ,NTK should work fine when my upstream 02 sensore failed i just replaced it with a Denso oem one right from honda whatever You do just dont use a bosch 02 because hondas are very finicky i would stick with Denso

 
Rep Power: 518

which brand was originally installed by the factory? DangerZone site said ntk


Imo they are equal quality for this case

 
Rep Power: 134

I guess I never actually saw the one from the factory; it had a Denso on it when I replaced it in January, so that's what I used.

I just got a 20% off code from Advance, so I ordered one up. With tax and free shipping: $40. Not bad.

Thanks for the help so far. I'll update with results once I change it.

 
Rep Power: 134

And the new NTK 24242 O2 sensor is on. I've reset the ECU, and I'll update the thread if it comes back on in the near future. Thanks everybody for the help

Maybe now I should take a look at the P0497 code.