so i check up on a code i got last night and i found out it was a o2 sensor that i was told had ice buildup on it. i was driving today and the check engine light just shut off. does that mean the problem went away, or the switch thawed out? still trying to figure out the obd2 system. even tho the check engine light came back on tonight, i was wondering if the light clears because the problem goes away, or if it figures you've seen the light and shuts off. but the light is on again. for the o2 sensor or o2 switch. so if anyone knows a good way to keep that from freezing let me know. thanx

 

what code is it? do you have a reader or did you go somewhere?

theres not much you should even need to do if its " freezing" its on the exhaust pipe and will warm up pretty fast.

 

maybe its not the o2 sensor, it the one on the intake, it a switch

 

scratch that last one, it is the exhaust, o2 sensor bank 2 sensor 1, the guy at autozone said it was just froze, the light went off while driving earlier but came back on, should i worry at all?

 

Bank 2 is the side of the motor that cylinder 1 is NOT on. Sensor 1 is is pre-cat. Just change the sensor? The guy at autozone doesnt know what hes talking about, it cant freeze unless the outside temperature gets that cold. If that is the only code on there I would change the sensor. A bad O2 sensor will cause the computer to run a fuel mixture which is not optimal because it is receiving an incorrect signal from the O2 sensor usually resulting in worse gas mileage. It can also make it run lean and starve the motor of fuel. It can also cause misfires, so if you refuse to change the sensor just keep an eye on it. Just because the light is gone doesn't mean its fixed. Your computer adjusts fuel mixtures using different input sensors to find the best mixture (ie. MAF, ECT, MAP). The job of the O2 sensor is to read the mixture after it has burned and the computer adjusts accordingly. In some conditions your O2 sensor may get a good reading on the mixture, in other conditions it may not (different outside temperatures, different engine temperatures, etc). The first sensor before the cat plays a major role in fuel mixture, the second O2 sensor past the cat is mostly there to make sure the cat is working efficiently.

 

he said it was the sensor in the intake that was frozen, is that possible to throw a light

 

Nothing on your car should freeze. Where would this source of extreme cold come from? If by freezing he means getting stuck, none of these sensors have moving parts so there nothing to freeze...

If by sensor on the intake he is referring to the mass air flow sensor or ACT (air charge temperature) sensor then the computer has seperate codes for those sensors, you would not get a bad sensor code.

 

well if it didnt freeze, what would cause the light to go off then come back on later?

 

Lets try this again


I dont get what the question is here. If you have a code for a bad catalytic converter you dont change your tires do you? You have a code for an O2 sensor, change the O2 sensor. Like I said before, just because the light is gone, doesn't mean its fixed. Your computer probably just liked that mixture under those conditions when the light was off. Unless it is snowing where you are, I dont see how it is possible for the O2 sensor to freeze.

 

1: i was towing out in heavy snow the night before. and 2: the question is, will a frozen sensor due to moisture in the intake cause a sensor in the intake to freeze. this is how i had it explaned to me. i was wonderin if somehow the 2 were linked. i really dont wanna waste money or time fixin **** that aint broke

 

if your getting o2 codes, then you have o2 problems, if its something else, then the code is going to read something else.

pick up a tuner or go to autozone and get the code if your light is on, post on here or google it and figure it out.

the light to come on and off, can happen a lot, i've had some egr codes pop up and go away. haven't changed much on it but it hasn't been on there for a bit.

 

I would have the code read at more places than just Autozone as well. My truck threw a code last spring for a faulty o2 sensor and it ended up being a vacuum leak. Guess who I had read the code? Thats right, Autozone. After I found the leak I had them read the codes again (before I fixed it) and then went and had them read else where. Autozone's computer said nothing about the possibility of a vacuum leak and the other place's computer did. I fixed the vacuum leak and within 15 minutes of driving the CEL cleared up and has not returned since.
NOW, on that note, If you are convinced its not your o2 sensor... and there is a minuscule chance that it's not.. then you need to put a little more effort into finding out what is wrong. The fact that you stated that the truck had endured long periods of idling and towing would immediately lead me to believe that it is in fact the o2. Higher than normal exhaust temps and extra fuel deposits from long periods of idling could indeed foul the sensor. You may even want to check for broken or melted wires that are only making contact under certain conditions.
See, there are a lot of options. You have to weigh out the ones that are logical from the ones that just plain do not make sense and go from there. The guy behind the counter at Autozone is not a mechanic and probably never has been or will be. All they are there to do is look up part numbers and usually give you the wrong parts haha.

 

lol tru on the wrong parts. i have pretty much no knowladge to how any of these systems work and i dont know the terms that are put out in the codes, but i am getting a better idea as to what i gotta fond now. i was just thrown off by the fact that it shut off. i thought that ment it was fixed or it was a false reading. but i do plan to look into it. i am gonna re-read the code an i will post it up herte. what do you mean a vacuum leak? is that dealing with the intake. pardon my lack of knowladge on motors. guess thats why i'm here

 

Yes a vacuum leak deals with the intake side of the engine. I had a rubber elbow on a main vacuum line that had a hole chaffed in it by my intake hose.. But I also have a 4.0.

 

^mine had the same problem

 

how hard was that to fix

 

^fix what

 

The rubber elbow? It was as easy as moving the intake tube out of the way and pulling the old one off and slipping the new one on. 15 minutes work time with a cig break haha.. I doubt that is your problem though. My truck had a very rough idle and would eventually stall out after about 5 minutes if I didnt tap the gas.

 

the vacuum leak

 

well you would'nt have that hose on your truck...its only a 4.0SOHC issue...the best way to check for a vac leak is to spray all of the lines with carb cleaner and you will hear the engine sound change if you find a leaking hose

 

gotcha, i'll eventually go inspect the o2 sensors to see if somethin is up. but i'll keep it in mind as that was one of the causes listed. but i doubt it

 

Trying a different place to read codes would be pointless. All the machines read the same codes. These codes dont usually tell you what part has gone bad. It just tells you what is being affected by what is wrong. If you have a vacuum leak the computer cant recognize that. It may throw an O2 sensor code because you have a large amount of unmetered air entering the combustion chamber and the O2 sensor will read that your mixture is WAYYYY lean, but the computer didnt measure that much air going through the MAF so it thinks the O2 sensor is just sending a faulty signal, and throws an O2 sensor code showing that it is way out of range. In this situation you will usually experience driveability issues because the computer cannot add enough fuel to compensate for the large amounts of unmetered air entering the engine.

In a situation where the O2 sensor actually is sending a faulty signal, the computer can compensate by just dumping a bunch of fuel into the engine usually not resulting in driveability issues but only in worse gas mileage.

To be honest with you I really dont know if a frozen O2 sensor can throw a code. I would really have to guess no. I dont know for sure on the rangers, but most cars have a heater circuit to help get the O2 sensor hot and in operating temperature, what that says to me is that the computer knows there is a warm up period for the O2 sensor. If anything the +2000* exhaust gases coming down the pips will help thaw it out pretty quickly.

If the light comes back on my guess is you need a new O2 sensor.

 

You can never have too much information. I threw a bunch of money into a vehicle ONCE trying to fix a stupid simple problem and I will never do it again.

Back on topic..

rangerstepside - In your case with the given scenario I would put money on it that your o2 is done for. Just out of curiosity, how many miles are on your truck?

 

That doesnt make sense though, all OBDII code readers are going to pick up the same codes from the computer. One machine will not pick up anymore codes than another will. If you check the codes two different times, with two different machines, and you get different codes, it just means you have new codes popping up, not that the other machine didnt "pick them up".

 

dranger024- pushin 140k.

and for the result............drumroll please..................... good ol' iced up mass air flow sensor. cleaned it up a bit and the code cleared. back to 0 codes.