Maybe somebody will find this interesting.

As a follow up to my 2013 failure (we test every two years)...
https://www.hondaaccordforum.com/for...issions-55655/

The quick synopsis is my 1994 Accord LX 2.2L 4 cyl has failed emissions test; in apparently exactly the same way (high CO) three time over the course of the past 8 years... and in each case a new O2 sensor allows it to pass
2007 failed at 90K miles, passed when replaced O2 sensor.
2009 passed, 2011 passed,
2013 failed at 100K miles, passed when replaced O2.
2015 failed 101K miles (it was driven less than 1,000 miles over the past two years), and once again passed when replaced O2 sensor.

The three replacements were all Bosch, the original equip one was a Denso.

Is something wrecking the sensor?

Other explanations...? someone suggested jiggling the wires to the sensor is actually what's fixing it.

As you can tell, I don't drive the car much anymore -- so this is more of a curiosity!

I am the original owner.

 

Are you replacing the sensor each time with Bosch O2 sensors? Consider using Denso sensor.

Also, when was the last time you had a tune-up?
Spark plugs need to be NGK (2.50 each)

 

plugs: plugs were replaced twice: once many years ago at 30K miles. and the second time in 2013 just after the emissions failure in 2013 at 101K miles.
At that time 3 of the 4 plug wells were leaking oil.

None of that seems to have had any effect on emissions :-)

I wondered about the brand of sensor: yeah all 3 replacement sensors have all been Bosch 13075's. Mostly out of a combination of convenience / habit (third time's a charm!).
Apparently the denso part is if anything a couple of dollars cheaper -- i hadn't checked that out until now
Amazon.com: Denso 234-4620 Oxygen Sensor: Automotive

And the emissions test is sort of this high-stakes thing; and it only comes along every two years -- so it doesn't lend itself to tweaking and trying.

 

Any evidence of coolant loss? Silicates in coolant wiil damage an O2 sensor. A cooling system leak test may disclose a small loss of coolant by cylinder head gasket.

good luck

 

thx. Coolant hasn't really been noticably disappearing, but as i mentioned, with so few miles being driven, it may be a little leak not noticable to me... In any event i'll probably just continue to hang on to the car and since i don't use it much it's an easy fix even if i have to put in a new O2 sensor every two years!