lgs 98dx

Daughter's '05 Civic LX with 80,000 miles just threw P0135 code
my code reader shows:
O2 heater circuit, bank 1 sensor 1

I erased the code, but less than 1 minute after startup the check engine light came on again. Same P0135 code generated.
Tried disconnecting the battery to reset ECM but still throws same code

Factory Honda service manual goes on & on with electrical resistance tests
but doesn't appear to refer to the O2 sensors when diagnosis a P0135 code

However, I saw where there were other posts regarding replacing the O2 sensor(s) when a P0135 code was the issue

Looks like there are at least 2 O2 sensors:
1 just after the exhaust manifold
1 below the engine in the exhaust pipe

If it is one or both of the O2 sensors need replaced, then do I need to buy OEM honda part?

Thanks for the advice
Lg

SpdySylvrEX

p0135.doc

This is the Trouble shooting steps for a 2001, but they should all be the same...

If you can't read it or open it, let me know...This is the first time I have done this...

lgs 98dx

Document opened fine
I will go through the trouble shooting sequence listed and see what happens

Also, I did go to Honda this afternoon and tech said it is most likely #1 O2 sensor (top one), as they replace this item frequently on this engine. Although, occasionally there is an issue with a cracked exhaust manifold (already experienced that on my '98 Civic quite awhile back).
Thanks

SpdySylvrEX

yeah, that's your primary one. The one in the CaT is secondary. I believe they are supposed to be replaced every 60,000 miles (don't quote me tho)

If it is cracked you would know by a crappy sounding exhaust...you would know it when you hear it, it's a pretty distinct sound.

lgs 98dx

Installed OEM Honda O2 sensor #1 this morning and all appears to be good
Thanks for the help