Rear O2 sensors - CEL

[KaiserM715]

I got into some high water around the medical center yesterday (high enough to cover the rear O2s, unfortunately). Got to a high spot, waited it out. Went to my destination. A couple of miles after I left my destination, I get a CEL. I check it w/ the DashHawk and got a P2270 & P2272 (O2 Sensor Signal Stuck Lean - Bank 1, sensor2 / Bank 2 Sensor 2 - rear O2 sensors). I cleared the codes and drove 20 miles home w/ no codes. Checked the car out last night, took it for a test drive no codes. I pulled the rear 02 connectors apart and inside the connector was dry. Wife takes the car this morning, gets CEL. I checked it a few minutes ago. Same codes. Voltage readings with the engine running for B2,S2 are 0 mV with some spikes to 15 mV. B1, S2 voltages are below 50 mV, with spikes to 500 mV.

I am guessing the rear O2s are fried. Any other thoughts? Charlie?

My mods are long tubes, high flow cats, VMS tune.

BTW, the tranny and diff vents are the highest I have ever seen on a car. Tranny vent is on the back of the driver's side cylinder head and the diff vent goes up to the level of the trunk floor and is tucked above the rear subframe and suspension. I am impressed.

[-Ray-]

I don't know how they could have got wet. The sensor should still be good though. I bet it's something with how the wire attaches to the body.

[KaiserM715]

The connectors to the sensor pigtail are clipped onto each side of the tranny. Are you suggesting that the issue is there, or further in? If there was a wiring damage issue, I would have thought that the voltage would have been steady state (0 mV). There is a small exhaust leak at each of the band clamp locations right behind the cat. At idle, I wonder if the the water could have gotten in...

[GRRRR8]

It sounds like the sensor failed, BUT both at the same time......highly unlikely! I would be checking the 15 amp fuse (under hood) that says EMISSIONS 2. It is fuse 32. That is the power for both rear o2s

[KaiserM715]

I just checked it and the fuse is good. If the fuse was popped, I would have expected a constant 0 mV, right? With the small voltage spikes, there has to be some power getting through and the wiring harnesses looked good when I checked them last night.

[GRRRR8]

Technically the rear O2s should be turned off in the tune. I am still looking at a flow chart. Give me a sec....

[KaiserM715]

Technically the rear O2s should be turned off in the tune.
If I understand the VMS tune correctly, it only turns off the "error reporting" for the rear O2s, but I could be wrong...

[GRRRR8]

P2270

The ECM detects that the HO2S 2 voltage oscillations are slower than a calibrated value.
DTC P2270 sets within 4 seconds when the above condition is met continuously, or within 50 seconds when the above condition is met cumulatively.

P2272

The ECM detects that the affected HO2S is below 730 mV.
DTC P2272 sets within 1 second when the above condition is met.

This is saying that the O2s are stuck and not switching. How much water did you go through? Did water get in the exhaust? Any water that would get on the O2 tip would short it out.

[KaiserM715]

This is saying that the O2s are stuck and not switching.
That would seem to correspond to the rear O2 sensor voltages I was seeing.


Voltage readings with the engine running for B2,S2 are 0 mV with some spikes to 15 mV. B1, S2 voltages are below 50 mV, with spikes to 500 mV.

How much water did you go through? Did water get in the exhaust? Any water that would get on the O2 tip would short it out.

Unfortunately it was pretty deep. I am guessing it was about 12". The sensors getting shorted out what I was leaning towards when it first came up. I just don't want to be missing anything. I will likely go ahead and swap them out. Thanks for looking into it, Charlie. Anything else I should look into? I love this car and don't want anything to get screwed up.

I am still pretty agitated about the water (my wife can attest to it...), but I got into a situation where I just had to deal with it. Next time I have to go that way with rain / water like that, I will take the Raptor and live with the consequences of tight spots in parking garages.

[GRRRR8]

Truthfully it won't effect the way the car runs since they are for monitoring the cats and turned off. My guess is the exhaust sucked water in and it shorted the heater part of the O2. Get Delco O2s for it.

[KaiserM715]

Truthfully it won't effect the way the car runs since they are for monitoring the cats and turned off. My guess is the exhaust sucked water in and it shorted the heater part of the O2. Get Delco O2s for it.
The car runs fine, but I will have to get it fixed so I can get my Houston inspection sticker. The CEL will prevent that. I will get the Delcos from either O'Reilly (shown as special order) or XL Parts.

Thanks for the help.

[GRRRR8]

Any time!

[KaiserM715]

I am seeing the Delco part number as 213-4325, which is listed as "position 3" for the O2. Interesting.

[KaiserM715]

Everyone is either sold out or has to special order these. Never knew they would be so hard to get a hold of :( I have them on order.

[STL_G8GT]

Everyone is either sold out or has to special order these. Never knew they would be so hard to get a hold of :( I have them on order.

You ask greg at pace? If not him try Scoggins Dickey...

[-Ray-]

Everyone is either sold out or has to special order these. Never knew they would be so hard to get a hold of :( I have them on order.

I have two rear O2 sensors sitting on a shelf bagged up.

[todds87ss]

Just a question, here... 1 foot of water should not be enough to make it into the exhaust pipes, particularly with the car running. Plus, once the O2s dried out, they more than likely would either work or not. I suspect water in the wiring, which would take a long time to dry, affecting the outputs. I'd give it some time. As Charlie said, it does not affect the way it runs. Just keep resetting the codes to monitor the frequency of lock in.

[Got 8?]

Holy crap !!! I'm having the same problems...drove through some high water on the way to work during all the rain earlier last week...took the wife's TBSS the rest of the week...got an appt. at the stealer tomorrow to see what's up...Will let you know what they find...

Oh forgot...car is stock and also after I filled up the mileage dropped off almost 10mpg at 55 mph with the cruise set...and the car is hard to start and will sometimes take multiple tries to get it running...once it's up and running seems to run fine...

OnStar said 4 codes:

p0170
p0174
p2270
p2272

[Got 8?]

Bad news for me...stealer says fuel pump...

[KaiserM715]

Well, one of the two has decided to work, but the other is still dead.

I have two rear O2 sensors sitting on a shelf bagged up.
Ray, I got them today, thanks for sending them. I will put them in tomorrow night.

[-Ray-]

Cool.

[todds87ss]

Holy crap !!! I'm having the same problems...drove through some high water on the way to work during all the rain earlier last week...took the wife's TBSS the rest of the week...got an appt. at the stealer tomorrow to see what's up...Will let you know what they find...

Oh forgot...car is stock and also after I filled up the mileage dropped off almost 10mpg at 55 mph with the cruise set...and the car is hard to start and will sometimes take multiple tries to get it running...once it's up and running seems to run fine...

OnStar said 4 codes:

p0170
p0174
p2270
p2272



I have not been on here in a few days. sorry, Zed. I have a scanner with me most of the time, if you want to meet and have a look at it..or if you think the dealer has it correct, go with that. With the hard starting, it does seem fuel pump related, though. Probably another wiring issue, as the pump is very well sealed in the tank...

[GRRRR8]

It is possible that water got into the connector that is located on the passenger side of fuel tank. Unplug it and blow it out and retest.

[KaiserM715]

I swapped the rear O2s for the ones Ray sent me. According to the O2 voltage readings, I am pretty sure that Bank 1 is fixed. Bank 2 starts @ about 480mV and quickly drops to 0 and stays there. When I get another free evening, I am going to swap them side to side and see what happens. Bank 2 might have been DOA :( We will find out!

[-Ray-]

Let me know Will, both of those O2's should be good.

[KaiserM715]

Swapping them side to side will clear it up. If that is not it, I will have to start doing some research as to what else it could be.

[Got 8?]

I have not been on here in a few days. sorry, Zed. I have a scanner with me most of the time, if you want to meet and have a look at it..or if you think the dealer has it correct, go with that. With the hard starting, it does seem fuel pump related, though. Probably another wiring issue, as the pump is very well sealed in the tank...


It is possible that water got into the connector that is located on the passenger side of fuel tank. Unplug it and blow it out and retest.


Thanks guys...but its at the dealer and they quoted me around $1300 to fix the pump and $1800 for the pump and a 100,000 mile tune up (plugs, fuel induction cleaning...yada, yada) ...yeah I know I'm getting royally screwed but I need my car back cause I'll be out of town this weekend and the wife will need something to drive cause I'll need hers to tow my trailer...

Long story short...they didn't have the pump on site so I had to leave the car there...loner vehicle was out so I had to rent a POS Toyota Corolla...pump came in but the nipple on it was broke (just my luck...had the EVAP canister replaced a year ago almost to the day and they didn't have it on site and it was also broke when it came in)...I think the tranny in the wifes vehicle is starting to let go...oh and to add insult to injury...I came home and the tank on the toilet in my daughters bathroom was leaking....


2012 isn't starting out good for me...I need a rock to crawl under...:cry:

[todds87ss]

yes, you are taking a HUGE one in an uncomfortable place. Is it too late to call Kurt (Victoria)? I'm certain that LSX can have it back to you with a much quicker turnaround time (and the dealer is going to end up having parts issues - guaranteed!) and save you at least a grand.

[Got 8?]

Probably too late already...I'm sure they have the suspension down already and are waiting on the part...

[KaiserM715]

As reported by the wife, no CEL and the voltages are now all looking somewhat normal (I left the O2 sensor page up on the DashHawk). I will give it a check again tonight.

[-Ray-]

Sweet

[Got 8?]

Update :

New fuel pump came in in the afternoon, not morning like they said, and said they wouldn't finish it today...they are "hoping" they can finish it tomorrow !!! :grr:

This will make four days in the shop...:bang:

[KaiserM715]

As reported by the wife, no CEL and the voltages are now all looking somewhat normal (I left the O2 sensor page up on the DashHawk). I will give it a check again tonight.
I checked them last night and they were cycling fine, so problem fixed!!

Sweet
Indeed!!

[MoonPie]

I'd tune them out and ditch the fucking cats if you can, emissions regulations are fucking stupid anyways. The catalytic converter reduces the amount of carbon monoxide but also releases nitrous oxide which is 300 times more harmful to the atmosphere/environment than the gass the cats are trying to prevent from being released.

[KaiserM715]

My current setup will pass Houston emissions, so I am stuck with what I have. Anything less and I stand a chance of not passing.

I'd tune them out and ditch the fucking cats if you can, emissions regulations are fucking stupid anyways. The catalytic converter reduces the amount of carbon monoxide but also releases nitrous oxide which is 300 times more harmful to the atmosphere/environment than the gass the cats are trying to prevent from being released.

[todds87ss]

Update :

New fuel pump came in in the afternoon, not morning like they said, and said they wouldn't finish it today...they are "hoping" they can finish it tomorrow !!! :grr:

This will make four days in the shop...:bang:

I saw you on the road this AM...I assume everything is good?