Honda Pilot - Honda Pilot Forums banner

21 - 40 of 43 Posts

·
Registered
Joined
·
10 Posts
Just completed the O2 Sensors

Agree with the above posts - not an easy thing to get the upstream connector off the metal mounting bracket. Mine has 213,000 on it, and the post was a bit rusty, and I think the rust expanded the size of the metal bracket slightly and it wouldnt budge, even with plastic tab pressed to release it.

I ended up detaching the mounting bracket (12mm bolt into head just above connector), and then unscrewing the sensor from the pipe and pulling it up into the engine compartment. When I did this, I had enough play to get the connector on its side. Once I could get access, I used a sharp utility knife to cut open the back part of the connector where it wrapped around the metal bracket.

Given that I was replacing the sensor, damaging the one I was removing seemed like an acceptable trade.

Lots of cuts on my arms and hands from this one.
 

·
Registered
Joined
·
21 Posts
Wanted to add my $0.02 to this discussion.

Replaced the rear downstream (B1S2, bank 1 sensor 2) O2 sensor today on my wife's 2006 Pilot with 259k. Job took about 1.5hrs. The sensor actually came out of the exhaust easier than I expected. The hardest part was getting the old plastic clips out of the brackets! Those damn things are a pita.

But after reading the tips here on the forum, the job wasn't too bad. I unbolted the connector bracket, which made things easier to disconnect.
Seth
 

·
Registered
Joined
·
2,571 Posts
Same O2 sensor since 2003 at 228k miles!
 

·
Registered
Joined
·
482 Posts
Is it a contest? It's recommended to replace them at 100K. I replaced all mine on my 08 Odyssey at 170K (they were original as I bought the car new) and gas mileage jumped from an average of 14.5 to 17.8. That means old, worn out O2 sensors were causing the PCM to add more fuel that the engine didn't need. That means unnecessary stress on the catalytic converters. I never noticed that the engine had lost some of its power until I took it for a drive afterwards. It was noticeably smoother and has better acceleration. I replaced all four since the fronts are AF ratio sensors and the downstream sensors also contribute to fuel trim.
 

·
Registered
Joined
·
2,118 Posts
Should this be considered a tacit maintenance item? Like changing out your PCV valve or periodically checking the torque on your spark plugs? (I've done both.)
 

·
Registered
Joined
·
482 Posts
I've read places that say they have a service life of around 100K. Whether or not you should replace them at 100K would obviously be a debate. I replaced all four at 170K and they were obviously worn out, even though they were still doing their job and not setting any codes.

If you have a scan tool you can check your fuel trims periodically and look for trends. What I saw was +10-20% on the fuel trims between LT and ST combined. This means the PCM is compensating for what it sees as a lean condition and adding 10-20% more fuel to keep in proper fuel control, but not yet enough to set a code and a check engine light. I checked lots of other things, i.e. vacuum leak, mass air flow, etc. and couldn't find anything else. I finally decided at my mileage it was worth it to just replace the sensors. I started with the front O2's (actually air/fuel ratio sensors or "wide band" O2's.) That brought my fuel trims down a bit but after a few weeks they were back up again. I then changed the rear O2 sensors and my fuel trims have actually gone slightly into the negative and my fuel economy is back where it was when the vehicle was new.

I've scanned other Honda V6 vehicles at 100-120K and not seen the same high fuel trim levels so changing at the O2 sensor manufacturer recommended interval isn't a hard and fast rule. By 150K I'd probably replace all four of them for sure and possibly earlier if you start to see higher than normal fuel trims on a scan tool (anything over 5-10% in any direction.) The caveat here is that there are other things that can cause lean conditions...the Honda service manual doesn't even have you check O2 sensors for lean/rich conditions but it was definitely the cause in my case.
 

·
Registered
Joined
·
2,118 Posts

·
Registered
Joined
·
482 Posts
You can also get them at RockAuto.com and I've found them to be a bit cheaper there. There should be a 5% off discount code here in the sponsor section of the forums. If not, try the Odyclub.com forums as I know there's one there.

To be honest, I think it's best to replace all four. They work in conjunction with each other. I wouldn't be surprised if changing only the rears might do the same thing as when I changed only the fronts. In my opinion, and from experience, if you're over 150K on the originals, definitely change them all. If you're under that then I'd only change them if they are setting a code or you have diagnosed a problem with them.

I've found that Honda uses both Denso and NTK. I just did a sensor change on a 2005 Accord (was setting a heater circuit code) and the factory original I replaced turned out to be a Denso. I replaced them all on a 170K mile 2009 Pilot a couple weeks ago and they were all NTK from the factory. If you can get a mirror on one of yours and see which it has then you can get the exact replacement. I put an NTK on in place of the Denso and it fit perfectly. The nice thing about getting the identical OE sensors is all the clips are in the right place and it makes installation a breeze. I think Denso and NTK will do the trick in either case, though.
 

·
Registered
Joined
·
2,118 Posts
I'm not finding them for a 2006 on Rockauto...

By the way, I'm at 220,000 km, or roughly 138,000 miles.
 

·
Registered
Joined
·
482 Posts
With only 138K I'm not sure that you're to the point where just blindly replacing all four sensors would improve anything. They may still be working just fine. Use a scan tool that supports live data and take a look at fuel trims and see if you're in the normal range. If so, then motor on. If not, then worn O2 sensors "might" be the issue.
 

·
Registered
Joined
·
5 Posts
OK, Apparently it didn't like my back up plan to include my link to the dropbox file(same file as attached)

A quick update on my O2 replacements. Wouldn't you know it, but once again I got the P0420 code. So I had the rear cat converter replaced at great cost. Yes, I bought the genuine Honda catalytic converter from Bernardiparts.com. Then when winter hit here in MN, I got the P0420 code again! I'm suspecting that the converter efficiency drops on really cold days. So I've learned to live with it. When it appears, I use my OBD2 scan tool to erase it and it doesn't come back for months. I'll try to attach the file again here to the forum.
 

·
Registered
Joined
·
20 Posts
OK, Apparently it didn't like my back up plan to include my link to the dropbox file(same file as attached)

A quick update on my O2 replacements. Wouldn't you know it, but once again I got the P0420 code. So I had the rear cat converter replaced at great cost. Yes, I bought the genuine Honda catalytic converter from Bernardiparts.com. Then when winter hit here in MN, I got the P0420 code again! I'm suspecting that the converter efficiency drops on really cold days. So I've learned to live with it. When it appears, I use my OBD2 scan tool to erase it and it doesn't come back for months. I'll try to attach the file again here to the forum.
I have the P0420 code on a 2007 Pilot I just bought so this thread and your posts have been useful. Any new update? Did you discover anything new to keep the code away? I was going to change the sensors and possibly the catalytic converter but after reading your post, I'm going to hold off. I was able to download the doc.
 

·
Registered
Joined
·
2 Posts
Just did this on a 2004. 143k. Thanks to all who helped out here. I will ad a couple of things.


1) The part of the clip that slides over the bracket is on the part you are replacing. Just slip a screwdriver down the bracket into the plastic and break that piece off.

2) Unbolt the bracket and follow the harness toward the drivers fender and you will see where it T's, there's a 10 mm hold down bolt, take that out and you will gain a bit of flexibility.
3) Tie a string to the old plastic plug before you drop it down
4) There are two plastic clips holding the wire, access both from down below. You can see how the clip works by looking at the one closest to the cat.




The rear is pretty much the same but much more accessible.
 

·
Registered
Joined
·
13 Posts
Please correct me if I am wrong. I got a bank1 sensor1 A/F error. Which from the research I have done is the sensor before the cat which is accessible to be unscrewed from under the car. It lies pretty much below the car about where the front passengers feet would be. The connection is under the hood on the drivers mid side against the firewall. I have read some contradicting posts so wanted to confirm I got the right culprit before I take him off. Thanks.

P.S, I wish I can find bank2 sensor2 just confirm I am right. Surprised at how hard it was to find a clear image of exactly where these sensors are on the net.
 

·
Registered
Joined
·
1,471 Posts
Yes, it is the firewall side A/F sensor on the exhaust manifold.
What specific code are you reading?
 

·
Registered
Joined
·
1,471 Posts
That's the O2 sensor on the firewall side, not the AF sensor on the manifold.
 

·
Registered
Joined
·
13 Posts
That's the O2 sensor on the firewall side, not the AF sensor on the manifold.
Ok that answer got me totally confused again. I can only find two O2 senors on the whole car. One on the manifold pipe after the Y and one on the CAT itself. Otherwise I just see two manifolds come off bank 1 and bank 2 whose exhausts merge at the Y. When you say the firewall side I have no idea what you are talking about.

The Error says o2 sensor heater circut (Bank1 Sensor 1) So this is not the A/F sensor?

I realized when I first posted I mentioned the error said, "bank1 sensor1 A/F error." but when I pulled it again it actually says. o2 sensor heater circut (Bank1 Sensor 1)

I am assuming it has to be coming off one of the exhaust pipes. I just don't see any other.

After looking at this Vid. I am guessing the 05 and the 04 are a lot different. While the connectors are in the same place it seems like on the 05 it is on the cylinder head but on the 04 it is on the exhaust manifold.
 
21 - 40 of 43 Posts
Top