Got a check engine lite on my 99 civic and ran the codes with my scan tool. The result was: PO135 O2 sensor heater circuit (bank 1 sensor 1). Is this the O2 sensor forward of the cat? Is there anything to replacing these other than remove the old one an plug in the new one? Anyone know whose got the cheapest replacement parts for this? Hoping to do this on my own if I can locate the proper part and correct loaction of the sensor. i looked a little online at most of the major parts stores ( i.e. autozone) and there is quite a few different sensors listed for this. I'm not sure which one I need. Lastly, I cleared the code to see if it comes back to buy me a little time to figure this out and gather info.

thanx

 

It should be teh sensor in the exhaust manifold. I dont know for sure, 'cause I only hae one of them. You dont necessarily need to replace the sensor. The code says that its the malfunction of the heater circuit. Search here for that, theres info on how to test the O2 sensor.

There are a variety of different o2 sensors that you can buy, ranging form universal to OEM. Most people would not recommend universal. I went with a Denso, which worked fine for me.

 

I would just replace the sensor before the cat and call it a day. I would also recommend using an OEM sensor. A day before you tackle this job you should spray the sensor where it meets the pipe with PB blaster to help break the corrosion and rust down so it can be easier to break the sensor loose with a 22mm wrench or o2 sensor socket.

 

whats pb blaster? similar to break-free or penetrant oil?

 

Heater sensor failure code are usually 99% o2 sensor failure its the one on the rear bank before the cat.

 

PB Blaster is the shit! The best penetrant I've used. When I had the heater circuit malfunction I just replaced the O2 sensor, not worth the hassle of trying to fix it.

 

MAKE SURE that you do not snap the o2 sensor or strip the threads. I got an o2 sensor at the junkyard for free, and it worked great. there are plenty of civics at the junkyards... and this o2 sensor looked like it was just replaced too... saved me 50$ Yes pb blaster is a great penetrant.. you can get it at most chains like autozone.

 

Replaced the sensor myself. Not too bad. Soaked it in pb blaster and bought the special crows foot style socket. All for around a hundred bucks - part, tool, and pb blaster. So far the CEL has not come back. Lets keep our fingers crossed. Advance auto parts stores are liquidating all of the Ampro brand stuff at 75% off. Seems this brand has been discontinued. Had to pick up a few tools while I was there!

 

yea its the sensor in the manifold, thats the same one im throwing right now thats causing alot of problems. oh and by the way is you car engaging vtec fine??? where is it hitting at 5500 or later??? i just wanted to see if anyone else was having the same problem.

 

hum let see..
i have an error from o2 heater sensor too ...
the only problem i had is sometime i have an abnormal cutoff at 4800-5000rpm
i only have to cycle my key and i can reach more than 5000rpm..

this is happening when i rev up to 7000-8000rpm and going less than 5000rpm and tryin to go back to +5000rpm..CUTOFF!

dont know if this could be because of this sensor...
but if im driving normally and sometimes accel .. going great not having any troubles..
and the VTEC working good... but im using a VAFC2 to engage it at 5200rpm