bad 02 readings

[richardb200373]

So ideal reading is 0.45 volts for an 02 sensor right? Mine reads 0.13 on average. If I rev up the engine, it will go almost to 1.0 and drop back down. I replaced 1 (I have 2 on 2002 jeep 4.0L) but both still have the same reading. Why is it so low? Then engine is warm when testing. Any thoughts? Please help.


Ok, hold on, went and did another check. With my multimeter set on 20, on battery of course, reads 13.6v. On the 02 sensor, it fluctuates at 0.04 to 0.05, is it supposed to be 0.045 on the reading? I'm getting a little mixed up on this. Checking my efie to set it, it will go from 0.000 to 0.60, that is the furthest I've taken it. Someone please get me on the right path here, this is driving me freakin insane! One other thing, my engine light has been on forever, the codes lead to 02 and 0bd problems. I had the efie on with no hho as I was rebuilding. It was set on about 0.22. The other day the check engine light just went off. The minute I hooked HHO backup, it came on. I've been playing with the efie for a few days now and not getting any better, maybe a hair here and there.

[HiTechRedNeck73]

1st problem... you should make sure you car is running with no errors before installing an HHO device... otherwise you're chasing your tail trying to find the problem when a CEL does light up...

personally I think you guys are looking at the o2 sensors wrong... it's not a constant voltage that goes back to the ECU... it's a pattern... a wave pattern, and looks something like this:



now this is an example... my car has 4 o2 sensors... on these charts, the top are sensors before the cat, and the bottom are after the cat... make one is on the left and bank 2 is on the right... for my car, you will notice that the sensors after the cats usually don't get higher than .25volts... where the ones before the cats range from below .25 and pulse up to 1.02...

the point to all of this is... you need to know what your vehicle does so you can mimic it... so the ECU truly thinks everything is "ok" and then you will not have as many problems...

I'm working on my cell, so I can't give any advice on your setup... but you should find out what your vehicle's sensors are saying to the ECU before you go changing it...

just my .02, hope it helps...

[H2OPWR]

So ideal reading is 0.45 volts for an 02 sensor right? Mine reads 0.13 on average. If I rev up the engine, it will go almost to 1.0 and drop back down. I replaced 1 (I have 2 on 2002 jeep 4.0L) but both still have the same reading. Why is it so low? Then engine is warm when testing. Any thoughts? Please help.


Ok, hold on, went and did another check. With my multimeter set on 20, on battery of course, reads 13.6v. On the 02 sensor, it fluctuates at 0.04 to 0.05, is it supposed to be 0.045 on the reading? I'm getting a little mixed up on this. Checking my efie to set it, it will go from 0.000 to 0.60, that is the furthest I've taken it. Someone please get me on the right path here, this is driving me freakin insane! One other thing, my engine light has been on forever, the codes lead to 02 and 0bd problems. I had the efie on with no hho as I was rebuilding. It was set on about 0.22. The other day the check engine light just went off. The minute I hooked HHO backup, it came on. I've been playing with the efie for a few days now and not getting any better, maybe a hair here and there.

If you add too much voltage to the 02 sensor your ECM will thing the 02 sensor is bad and go into limp home mode. The check engine light will come on and the ECM will set your fuel mixture to all the way rich to prevent a lean burn condition. Too lean a mixture will cause high cylinder head temps and possibly burn your pistons. Ignore the after cat 02. Start with the front 02 and start adding voltage slowly. It is a very tedious process but the gains are worth it. The readings you are getting are normal. The lower the voltage the richer the air fuel mixture is. When you add too much voltage at one time the ECM adds more fuel and expects to see a substantial voltage drop. If you are adding too much voltage the ECM does not see what it expects and goes into limp home mode. If this happens just unhook your battery for a couple minutes. That will clear the codes. Drop the amount of voltage you are adding and start over. GO SLOW AND YOU WILL GET GAINS.

[bigapple]

So ideal reading is 0.45 volts for an 02 sensor right? Mine reads 0.13 on average. If I rev up the engine, it will go almost to 1.0 and drop back down. I replaced 1 (I have 2 on 2002 jeep 4.0L) but both still have the same reading. Why is it so low? Then engine is warm when testing. Any thoughts? Please help.


Ok, hold on, went and did another check. With my multimeter set on 20, on battery of course, reads 13.6v. On the 02 sensor, it fluctuates at 0.04 to 0.05, is it supposed to be 0.045 on the reading? I'm getting a little mixed up on this. Checking my efie to set it, it will go from 0.000 to 0.60, that is the furthest I've taken it. Someone please get me on the right path here, this is driving me freakin insane! One other thing, my engine light has been on forever, the codes lead to 02 and 0bd problems. I had the efie on with no hho as I was rebuilding. It was set on about 0.22. The other day the check engine light just went off. The minute I hooked HHO backup, it came on. I've been playing with the efie for a few days now and not getting any better, maybe a hair here and there.

Also, with the Check Engine light; unplug your battery for a couple minutes to reset your ECU and start fresh with a mixture. I had some issues with my generator when it was installed (left it on and the engine gulped some water). The knock sensors set off an engine code and there were probably others there. I did seafoam treatment to clean out what I messed up, and unplugged the battery to reset the computer. The light is off and I know I'm safe to go into the testing phase with different types of injections.

Might not be the fix-all but it's definitely worth a try. Unplug the battery and let it sit for a minute and then plug it back up. Might get rid of that light.

[richardb200373]

Thank you both, you are definitly right on those answers. Redneck, my jeep also has 4 sensors like you say, 2 in front and 2 after the cat. I assume the other 2 after the cat will not need to be messed with right? Actualy, on mine, the top sensors are right at the manifold, then there are two big tubes which I assume are cats; but, there appears to be another cat or something further down the exhaust line. I know quite a bit about vehicles but I am deffinitly not a mechanic.

I ran the vehicle a while ago about 60 miles. My reading did come up on the new 02 sensor, seemed normal, about 45ish fluctuating, ok, got that one down. The second one was only about 35, so I stoped and bought another new sensor and am going to replace it and hopefuly my little magic ferry will show up and turn off the engine light.

Thanks again for your help guys, I'm sure I'll be back for something.

[richardb200373]

Big apple, I had an explorer like yours before my jeep. Anyway, my jeep and your explorer are about the same engine, etc. other than straight 6, what kind of gains are you seeing? Thanks

[HiTechRedNeck73]

Thank you both, you are definitly right on those answers. Redneck, my jeep also has 4 sensors like you say, 2 in front and 2 after the cat. I assume the other 2 after the cat will not need to be messed with right? Actualy, on mine, the top sensors are right at the manifold, then there are two big tubes which I assume are cats; but, there appears to be another cat or something further down the exhaust line. I know quite a bit about vehicles but I am deffinitly not a mechanic.

I ran the vehicle a while ago about 60 miles. My reading did come up on the new 02 sensor, seemed normal, about 45ish fluctuating, ok, got that one down. The second one was only about 35, so I stoped and bought another new sensor and am going to replace it and hopefuly my little magic ferry will show up and turn off the engine light.

Thanks again for your help guys, I'm sure I'll be back for something.

have you done a key dance or OBD reader to see what your errors are?

the key dance is a chrysler thing, turn the key on (the key must turn all the way on, but not start the engine) then off (off must be off not accessory) twice, the on again and leave on (within 5 secs)... this will use the odometer display to give you the codes... write down all the "Pxxx" codes and either look them up or post them here and I can help you... you need to let the computer work for you not fight with it... if you post your codes here, don't forget to include year, make, model, & engine of your vehicle... if you want to look up your own codes, I suggest this site:

http://www.obd-codes.com/

you can gain direct access to codes by adding the code to the address above... for example, if I wanted to know about P0304 I would enter this address...

http://www.obd-codes.com/p0304

H2OPWR is right that most codes will cause a "limp mode" and you won't see any fuel savings... that is why it is so important to get them all gone and stay gone...

also, are you using EFIE on both of the upstream (manifold) o2 sensors... you must have one on each unless you have one that controls both at the same time... but you need to be able to adjust independently...

another question for you, did you try extenders 1st? it's my understanding from a few different sources that the extenders work on chrysler vehicles... but you have to double them up and get ones with a small hole so you can drill them out to customize for your vehicle... I'm just curious... heard that from more than just here and I'm trying to simplify my setup...

[bigapple]

Big apple, I had an explorer like yours before my jeep. Anyway, my jeep and your explorer are about the same engine, etc. other than straight 6, what kind of gains are you seeing? Thanks

You are right on that since both have a displacement of 4.0L. I never got my generator completely running without leaks because the gasket sealer I was using was actually affected by the electrolyte and caused it to spring leaks. But I know that once I get Neoprene rubber cement, I won't have to worry about leaks because it doesn't react with KOH or NaOH and it's super adhesive. I'll keep you posted when I get results with that. Right now I'm experimenting with water vapor injection and I'll stack that with my hydroxy generator once I get everything sturdy and up and running.

[JonDoh]

Thanks to all! You guys helped me out just by reading your posts!

[richardb200373]

Thanks to all for replys. Redneck, I saw one of your posts about getting the codes which I did yesterday, thanks, that helped. My engine light is out now thank God! I still did the key thing anyway and these are still coming up : P0031, P0051, P0136. If I remember, 136 is an 02 error, and I'm pretty sure the others are too. I coundn't find those too on that site you were talking about, but I think it is low voltage code on 02. A few others that came up a few days ago was P0152, P0175, and P0460, I think all 02 related also.
ANYWAY, here's what happened, I replaced 02 sensors a while back, got to thinking and looked at the box, they gave me the sensors for after the cat, got those replaced, still had the engine light on. I reset the ecu by unplugging the negative battery cable for an hour. Then I remembered someone saying to pull the fuse or relay under the hood for it also, well, did'nt find that one, but I did see a fuse that said 02, and guess what.....damn thing was blown! My luck. Oh well, played with the efie until the engine was choking, then brought it back to about 0.20, tried a few other settings, seemed that I had some change on about 0.30 but not sure, too many hills and mountains right here close to home, need to get out on flat interstate.
How much should I be moving the efie when testing?, 0.01, 0.05, ?
Thanks again guys, I'll keep you posted on my progress.
Richard