Hi, my name is Jake and i just joined. I have a 97 Eddie Bauer Edition Explorer. My engine light has been on and I took it to Advanced Auto to get it checked out. On the printout, I had two codes come up. One is PO135 (O2 sensor heater, circuit malfunction) (bank 1 sensor 1). The other is PO155 (O2 sensor heater, circuit malfunction) (bank 2 sensor 1).

The guy said to have it checked by a mechanic because they couldn't tell me exactly which sensors to get. So I'm wondering which O2 sensors do I need to get rid of these codes?

 

You shouldn't buy anything yet. First you need to find out why the code was set. I think that since there's a problem with both heaters the problem could be in the voltage supply for the heaters. That may be common to both sensors. I bought a Ford cd that covers mine and it gives all the info. you could ever use.

 

90% of O2 are good when replaced because the codes thrown are false, always test before throwing $$$$ away.

http://www.mr2.com/TEXT/O2_Sensor.html

 

Check mini fuse 11, ("hego system")under the hood in the power distribution box.

 

ok i'll try the fuse. it seems to be "chugging" also whenever i'm driving, and especially when i go up hills. I can also hear a "ticking" sound either in front of me or below me. Its not all the time, just usually whenever i'm going up hills. Anyone have an idea? probably not the o2 sensors then?

 

My 97 does that the ticking sound and just a little when the eng. is cold too. I found a crack in the right exhaust manifold. I'm pricing them as we speak.

 

clear the messages and wait a few days. If they come back on there is an issue.

there are 4 sensors, Bank 1 sensor 1 and 2 and Bank 2 sensor 1 and 2. The message is telling you which ones to replace.

I just had one replaced yesterday, the part is 39.99 and they charged me an hour labour. I was getting a message something about a rich mixture.

Good luck

Matt

 

Have you tested the O2s yet, or are you still talking about it??

 

I would replace the O2 sensors. While an above poster said that 90% of replaced O2 sensors were good, may I point out that over 90% of failed catalytic converters are caused by faulty O2 sensors, and these same O2 sensors that wiped out the cat, in almost all cases, test out as good. O2 sensors are supposed to be replaced about every 80,000 miles. Your owners manual may specify other intervals, which you should follow. In any case, you have codes for the O2s, replace them. They are many O2s that do not trigger codes that need to be replaced.

 

Hi Mr. Bear river. The first thing I want to say is that when I owned my auto repair busiess I could have made lots of money with you as my service writer. The reason I quit my own repair business is that I was and still am honest.
What is your answer to all of the heater circuits going bad at one time? I just bet if someone like the owner were to track this thing down that it would be found that something in the O2 heater circuit would be at fault. I bet if he replaced all the HO2 sensors himself then cleared the codes he'd still have the same code show up.
If I'm wrong I apologize. But I don't think so.

Dave.

 

Thank you DaveBB, most folk nowadays are replacement artists, hope the problem goes away. When the CEL comes on again they complain about the advice/technician.

I believe in diagnosing the trouble properly, the codes direct us to the potential area, but we still have to check/test the components in that circuit.

Many times I have found that the O2 code registers and the fault is corrected by cleaning or changing out a different part that did not throw a code.

Thats my 2 cents worth, I know you guys will do as you wish until the light goes out.

 

I am not disagreeing with you. What I am saying is that O2 sensors are a lot less expensive than the catalytic converters, and that the majority of catalytic conver failure are caused by faulty O2 sensors that do not trigger codes.

I am going to agree with you, that having heater circuit failures on multiple sensors is extremely unlikely, and that a wire has possibly been damaged or a connector is bad or half a dozen other possibilities. However, by the same token, the sensors probably have more than 80,000 miles on them and unless there is something to suggest the contrary, they should be replaced as part of a major tune up. In many cases, the potential fuel savings of a new sensor can outweigh the cost anyway.

 

This is what I did, I bought a autoscanner.
I have a Actron CP135. It was cheap from www.amazon.com.

The 1st time I used it, it saved me the $85.00 fee to find out why my check egaine light was on. "louse gas cap".

You can't guess at a late model car, it can't be done.
Once the government got into the car business it got really expensive and complicated to fix the average car, hence in self-defence the mfg's went into OBD2.

Buy a scanner!

 

Now it's chugging pretty bad, and it wont go over 2-2 1/2 rpms. Seems like i've been losing gas mileage too. I was on the highway last night and it was really "chugging" or "bucking." Like it's having trouble shifting gears or something. I know I got my light tested and it brought up o2 sensors, but it seems like something worse.

 

Hi. Are these the same symptoms you were having when you joined the group? Only worse. Way worse. If they are I have something you can try. I think your symptoms are unrelated to the code you got for the O2 sensor heaters. If you know where the Mass Airfolw Sensor is and what it is. Unplug it with your key off. Then take a drive and see if the symptom goes away. If the symptom goes away that means that the default info the computer is using is better than the input recieved from the sensor. Replace the Mass Airflow Sensor if this works.
It's the big thing in the air intake hose after the air filter box and before the throttle body. I think the plug has 5 wires. Not sure of that though. Unplugging it and running the engine will set another code but it will clear itself after a few drive cycles. Not sure how many.
Dave.