Guys & princess

My accord has 156k miles,98,ex,4 cyl,2.3l.I had code p0135(heater circuit malfunction (bank 1 sens1).I tried & changed two brand new o2 sensors(one from bosh(manufactured by denso),another one from majestic honda dealer part(denso)).Both threw the same code.I reset it couple of times.As soon as i start the car the code turns on.But when i had the old OEM,came with the car,i had no code.Now i put the old
OEM back in still it threw the same code.I checked the heater wires resistance (black colore wires) (25 ohm at cold),volt (12v).It looks it is in the recomm spec.Can you please anyone advice where do start to resolve it.

Once you but in the aftermarket sensor you probably blew the sensor heater fuse. Check every fuse in all 3 panels. I'm not sure which one does that circuit.

After that, all sensors will end up with that code as there is no 12 volt feed to the sensor connector.

The aftermarket sensors usually switch the sensor ground terminal with the sensor heater power wire and the fuse pops.

Civics are really cool with this as the same fuse also sends power to the IAC and the car actually idles too fast when the fuse blows and you end up with both front and rear sensor heater codes.

I beleive there is only one fuse to check which is under driver side 15amp fuse
(ECU).That looks fine.Whatelse could be?

I had p0420 (cat convertor code) before this code.I changed the cat now i didnt have p0420.After i changed o2 sensor as maintenance item,p0135 is on.Princess or anyone advice me please.

It sounds like Fred gave some solid advise there.

Take off all 3 fuse panel covers and look around. There's one on the drivers side, passenger side, and the engine bay. Check every fuse. Report back. :yes:

Yep, take advantage of the sage advice from FredSVT. Once all fuses have been ID'd, you'll know more if not already finding the problem.

Did you replace the cat with a Honda unit or aftermarket? These cars do not like non-oem cat units.

Also, How did you reset the ECU?
Because, some people think disconnecting the Battery is this. Correct is, Passengers side Fuse# 13 (I think?), or with a scan tool...

I am going to check all the fuses as you said.
I reset the mil by scanner,removing battery,removing the fuse,didnt work.I replaced the cat with regular magnaflow.
thanks

I checked all the fuses.Looks fine.Now i want to check PCM side connection.
Can someone please give me the PCM location & pin diagram for 98 accord ex,4 cyli,2.3l.Thanks

Is the heater circuit voltage controled by relay/pcm?.