Started car (2005 S-Type 3.0 67k) this morning from cold- Had a CEL, scanner later read 1646 and 1647. I has been very hot here the last couple of days - 102-104. 2 or 3 years ago had same code/ same time of year- it appeared for 2 days intermittently and then went away never to be seen again until today.

Could be the ecm is being fooled by the heat issue of the weather or finally they are going out. I will see if I develop another code on them over the next couple of days.

Several questions:

1. I have seen on -line at auto parts stores both 2 wire and 4 wire o2 sensors. Which one does this take? Any idea as to best place ans best price to get?

2. Do I need the special tool to remove or would penetrating oil and flat wrench work just as well.

3. And this is a more general and not as important question,- after clearing codes on a sensor- is it advisable to disconnect the battery and let the car relearn the sensors regardless of whether I just replaced them or or merely cleared the codes.

Thanks
as always

Tom in Dallas
2005 S-type 3.0 67k

 

1. the number of wires is not the issue, it's the kind of technology and detailed response
2. they can be very hard to get out or you might be lucky
3. if you change one, disconnect battery

 

I am not sure if I understand this. Would not the technology be determined by the number if wires. in looking at them it seems the number is 4- if i use 2 wire what am I missing for the car or the ecm,??

Thanks

Tom in Dallas

 

No. You can have any of the technologies with 2 or 4 wire. Don't buy the wrong ones!

 

Well I must be dumb on this one. I don't know what you mean by different technologies.

What does the standard 3.0 S-Type (2005) require. I am assuming they are using only one technology for the car- maybe a different one for the 4.2, but I don't have that, I have the 3.0. perhaps I can look and see how many wires there are, but I am the type that when I do a job, I get all the diagrams, know all the parts, have them already bought and get the job done. I am not going to start and take 2 weeks to do it and the price varies widely on these items. In looking at the stores online- it appears to be a 4 wire.

Is there any real difference in getting one wired with the toggle vs. getting on that I would splice into the toggle or do some of these toggles over time get negatively impacted by the heat?

Thanks

Tom

 

I replaced the O2 sensors on my S-type 2002 recently - your model apparently uses different model sensors but mine were 4 wire (for the heater) and exact fit (don't try to use one where you need to splice wires etc). Also you can potentially unscrew them without the sensor removal socket (I do have a couple of those tools) - you would need to unplug the O2 wires first, cut the zip tie if the wire is tied up so as not to touch the catalyst converter. A flat open-ended wrench with a long handle would do the trick. May need to be able to add something at end to gain leverage to break the nut free - they are stuck on pretty tight given the heat. The biggest pain is trying to do this under the car on your back.

 

2 are a specific wideband and 2 are non-wideband. Use google to understand if you actually wish to!!

 

I found the factory Denso sensors at Amazon and on EBay. Search the forum for the correct part numbers. I have an STR and only have those part numbers.

Don't try to splice anything. Just remove the old and screw in the correct factory sensor.


On the S-Type the O2 sensors are easy to get to. You might want to see if they will break free before ordering anything. If you are in a rust area it could be more difficult to get them out. I would buy the proper O2 sensor socket. They are not expensive and can be used on many cars. On the STR you can get them out with normal flat wrenches.

Your error code is for the heaters in the sensor. It seems odd that both sensors would lose their heaters at the same time?? I would clear the codes and see if they comeback. I had the same code but only on one side and it would set the light as soon as I started the car. I swapped the sensor to the other side and the code followed so I knew it was the sensor and not something else.

As JagV8 said we have 2 wide band sensors before the cats and 2 regular sensors after the cat. I don't think the ones after the cat have heaters? So your probably looking at changing the ones ahead of the catalytic converters.

I just clear the codes with a reader but you won't do any harm by disconnecting the battery but I find it a pain to reprogram the windows and other small things.
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Er... check the fuse(s) and relay(s).

 

Well, but of course, as a computer engineer, I always work in detail and step by step from the foundation up to the top point.

I have cleared codes, reset battery and have a 50 mile trip today- 2 ways and we will see. Same thing happened last year about the same time of summer and the same heat. I am wondering if the heated plugs reached their "optimum" limit and sent a false/positive. We will see in the next couple of days. They seem easy to get to and are 4 wires.

Thanks

Tom

 

They aren't too overly hard to remove, but if you can get to them on a lift it is easier. I took mine out and it did require a bit of effort, but wasn't too bad. I didn't use any type of penetrating oil, only because I didn't want any weird smell issues when I started the car back up.

 

The O2 heaters are only used in the first few seconds after the car is started. They only keep the O2 sensor hot until the exhaust gases build up enough heat to get the O2 sensor in the temperature range it's needs to work properly.

The heater codes almost always turn on the check engine light as soon as you start a cold engine. Because that's when the system needs them. I don't see any reason why they would even be on other than the engine starting?
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Have not had any further problem with the o2 sensors. This is what happened a year ago. Threw a CEL and then cleared and nothing more.

I have a simple theory and will be curious as to opinions.
I always use the the same gas from the same station about 98% of the time. I use Shell Premium as it is a top tier rated gas. It contains here- no ethanol.
I had been told these gas do not really like ethanol. Prior to my latest o2 sensor problem, I had a discount at what would be a Tom Thumb/Safeway store and perhaps once every year I use that. It was after putting about 3/4 of a tank full of that (still prem) that I had the o2 sensor fault as well as the MAF fault.

Drove the gas out and never returned. I am speculating that unless it is a huge coincidence that my engine just does not like the ethanol and throws out codes that may relate to it.

The MAF is just something I have learned to live with. Once about every 4 months, I will get a CEL and all codes are related to MAF (lean banks ect).

I will take it out. It does not look soiled or dirty anyway. Clean with MAF cleaner and good to go for the next 4 months. Air filter is changed every 2 months, no vacuum leaks, clean throttle, o-rings replaced on upper and lower IMT. regardless- 4 months or about later- cel with same codes, clean again and good to go. Must have a sensitive one. Did buy and try a new one from Autozone that was a Duuralast and immediately put me in RP. Cleared by battery- put old back in- fine- replace again with Duralast and RP immediately. That went back to Autozone.

justa few experiences.

Tom in Dallas
2005 S-type 3.0 67k

 

Tom,

Is it not a State law here in Texas that all fuel must contain 10% ethanol?

I got ethanol free gas in Oklahoma last week.

BTW.we always use the premium gas but get it either at Costco or Tom Thumb. never any problems. They sell tons of fuel at these stations so I know it is fresh.

 

I believe what you are talking about it the law regarding labeling of ethanol and at what % are they required to start using labels.

My point is that I am trying to find why twice in 2 years I have had so-called o2 sensor problems and the anticipated CEL and codes and then would completely disappear. it could be a glitch in the ECM, however the only event that this year that could have caused it was the last time I put in a non-top tier gas and I have heard from 4 respected jag. mechanics in Dallas plus the Jag Dealer in Dallas (less likely to pay attention to them) that these engines have funny things happen to them with ethanol. I know not- merely posing a question. Never known o2 sensors healing themselves and it happened one time last year about the same month and outside temp conditions (quite high0 and perhaps the o2 sensors were reaching their optimum and could not go further- whatever- the only thing that i could have done was use a non-top tier gas and I know that is as heavily debated as many other things. Just do not like anomalies without a reason.

Tom in dallas

 

Well maybe so but with my 2005 STR I have used gas with alcohol for many miles with no problems.

It's possible to have a random error but usually not the same one multiple times. Did you swap the sensors side to side to see if anything changes?
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Not a reason. Both times I had the CEL it showed that both were in failure- so switching did not make sense at the time. That is why I think it got a misread or glitch and I still like to know reason and the only time I can isolate is than one time change of gas. That may be completely off base, but was a change that could have affected. Also I am the type, if I am going to reomove the sensors to switch- they will be with new ones.

Tom in Dallas