Rep Power: 0

So here's the code:

P0135 O2 Sensor Heater Circuit Malfunction

I'm a bit confused as to what needs to be replaced?

Also, the guy told me that he wasn't allowed to clear it out, but he still let me use it and clear it out myself. I still have the check engine light on- but I'm not sure if it's staying on because it's still broke (aka the problem is still there), or because I didn't clear it out correctly.

Either way, doesn't really matter- my main question is what needs to be replaced? The O2 sensor? Just some random "heater circuit"?

Is this really important to be replaced? I've been driving 300+ miles with it like this, and if it's killing my engine it would be good to know.

Please advise!

EDIT:
My car is at 102,000 miles. As far as I know, the O2 sensor or any work surrounding it has never been done or replaced.

 
Rep Power: 517

When a heater is bad in an AF sensor, it takes about 60 seconds to reset the code and turn the light back on after you cleared it.

The majority just get the offending sensor replaced.
P0135 is defined as sensor 1, the upstream sensor, before the cat.
On an 05 it is an A/F sensor, not an O2 sensor. (Unless it is a GX)

Please please please use an OEM sensor.

If you had given more info, I may have been able to give the genuine part number. (US only)

DIY:
http://www.hondaautomotiveparts.com/ (seems to be down at the moment)
http://estore.honda.com/




Autozone: Turning your Honda into a Hyundai one part at a time.

 
Rep Power: 252

Haha,

I try to avoid autozone parts at all cost.

I remember replacing my bank 1 and 2 sensors because one of them went bad. Somewhere in the neighborhood of $500 from Honda.

I hear aftermarkets may cause alot of problems.

 
Rep Power: 0

This forum has really helped me in lot of DIY. I thought I will share my experience so others can benefit from it.

I have a 2004 Honda Civic LX coupe (1.7 liter auto). My check engine light came on last week when I had around 100500 miles on the odometer. I took it to AutoZone to read out the code.

The code was P0135.

Definition
A/F Sensor 1 Heater system malfunction
Probable cause:
Open/short circuit condition,
Poor Electrical Connection
Faulty A/F sensor

I did some research online and found out that the best replacement part is the Denso Air Fuel Sensor Direct Fit (Part # 2349005). This is the pre-cat O2 sensor. It had very good reviews and denso is the oem part supplier for this car.

I usually buy my replacements at Advance Auto Parts. The original cost was $156 and they had a discount of $50 for $150 or more and so i got this for $106+taxes.

Advance auto also loans tools for $30 deposit, so i got the special tool for this and changed the sensor it in less than 10 minutes. Try removing the old O2 sensor when the engine is little warm, its much easier than on a cold engine.

Once swapped, I drove the car for 20 miles and the code did not turn off. I let the car sit over night. Next day, started the car, as i was heading out for work, less than a mile (<2-3 minutes after sitting at a light), the light turned itself off.

So for people who are complaining that the light not turning itself off, let it sit overnight and try it the next day. I think the entry condition for the ECU to detect a good sensor might happen only when the engine transitions from cold to warm.

Dealer quoted me $325 for this job and I was able to get it done for $116.