Honda CR-V Owners Club Forums banner

1 - 4 of 4 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1
My 02 CRV Ex Awd has 103k miles on it and lately it seems to be getting worse gas mileage then usual. I tried doing all the usual things like changing the air filter, changing the spark plugs, checking tire pressure, checking for a locked brake caliper, fuel injector cleaner in the gas......etc. The car runs fine otherwise, it idles smoothly and has plenty of power it's just that the mileage has gone down about 4mpgs. So I plugged in my scan tool and everything looked fine there were no trouble codes but I did notice something strange with the upstream O2 sensor. Most cars I've seen the upstream O2 sensor switches rapidly from about .1v(lean) to .9v(rich) but mine is staying right around .620-.670v at idle as well as at 2k rpm. If the O2 sensor was bad it should set a code but I've read that they can become "lazy" or "biased" when they get old and it may not set a code. Does anyone know if this is a normal reading for the K24 engine? Any help would be greatly appreciated.
 

·
Registered
Joined
·
3,717 Posts
I don't know much about the O2 readings,but I believe it is supposed to fluctuate (rich/lean) pretty rapidly (aprox 8 cycle within 5 sec) when the engine is held at around 2000 rpm.
If your engine temp sensor is faulty or has a corroded connection, the computer may keep the engine running in the 'open' loop mode which means a much richer air/fuel mixture and poorer mpg.
If you finally decide to replace that sensor, I would suggest a Direct Fit Denso, and definitely not a Bosch.
Hopefully more experienced folks will give you the advice you ask for.
Check this link for some interesting O2 stuff: http://www.motor.com/article.asp?article_ID=589
Buffalo4
 

·
Registered
Joined
·
4 Posts
Discussion Starter #3
Thanks for your help Buffalo4. The scan tool shows that the computer is going into closed loop mode so the temp sensor is probably good. I've also heard bad things about the Bosch O2 sensors so I was planning to get the Denso #234-9005 which is supposed to be very similar if not identical to the OEM Honda part, I just want to confirm that the sensor is bad before spending $100. I think I'm going to check the O2 sensor connectors and make sure they are clean.
 

·
Registered
Joined
·
3,717 Posts
Sounds like a proper thing to do.
They are too expensive and sometimes a PITA to replace without determining if it is the problem.
Please post back on what you find.
Buffalo4
 
1 - 4 of 4 Posts
Top