I had a check engine light for high voltage in 02 sensor and running lean in bank one, both due to a faulty front 02 sensor, i ordered and NGK replacement reset the ecu by unhooking the neg, terminal of the battery, also pulling the 2 fuses in the fuse box, and im still getting the same CEL for the 2 problems...anyone have any ideas Thanks in advance

 

Could have been the other O2 sensor, there are 2 of them. Upsteam and Downstream. It measures the difference between the 2 to get a reading. HTH.

 

when i went and had the codes read at autozone they put them in the computer and both of them were for the 02 sensor in the header... so i dont know... thanks for the quick reply tho

 

First of all, go jump your service connector, and record the CEL flashes. Lets find out exactly what the codes are. Second, have you traced the wiring and made sure its not a wiring fault?

 

Find out which specific code you're throwing.

 

the code scanner would show a more accurate reading rather than jumpering the service jumper.

P0132 Primary Heated Oxygen Sensor (Primary HO2S) (Sensor 1) Circuit High Voltage
&
P0171 Fuel System Too Lean

I'm guessing on the second one since there are several that would indicate Bank1 (primary O2) lean.


if you're O2 is new you must have a wiring problem.
a simple volt meter will tell you if you have a wiring problem. tap into the O2 signal at the ECU, make sure that the voltage runs from .2-.8 while cruising, anything in that range is ok, outside that range is bad.

 

The OBD2 scanner might be more descriptive, but I would not say more accurate.
Plus, being an employee of the company where he tested it, I know for a fact that some of the older OBD2 scanners don't always have the right "message".

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by andyt &raquo;</TD></TR><TR><TD CLASS="quote">The OBD2 scanner might be more descriptive, but I would not say more accurate.
Plus, being an employee of the company where he tested it, I know for a fact that some of the older OBD2 scanners don't always have the right "message".</TD></TR></TABLE>
agreed, half the time the cheap generic OBD2 scanners that most places have are slightly off or flat out wrong. At least the ones that I've used are.

The reason I suggest everyone getting the OBD2 scanned code is that the OBD2 DTC codes tend to have a more focused diagnosis in the Helm manual.

 

the codes if i can remember correctly were po136 and po138, when i went there they told me that it was the o2 sensor located before the cat, and after reading i believe that its the one after the cat... if anyone can verify this that would be great... Thanks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by teg01type-r &raquo;</TD></TR><TR><TD CLASS="quote">the codes if i can remember correctly were po136 and po138, when i went there they told me that it was the o2 sensor located before the cat, and after reading i believe that its the one after the cat... if anyone can verify this that would be great... Thanks</TD></TR></TABLE>


P0136 02 Sensor Circuit Malfunction (Bank I Sensor 2)

P0138 02 Sensor Circuit High Voltage (Bank I Sensor 2)

looks like its the one after the cat

 

P0138 is the secondary

 

So you replaced the one before the cat, and now the you need the one after? Maybe they read the code wrong and gave you the front instead of the rear.

 

yea, im getting the feeling thats what they did...which pisses me off...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dave_B &raquo;</TD></TR><TR><TD CLASS="quote">So you replaced the one before the cat, and now the you need the one after? Maybe they read the code wrong and gave you the front instead of the rear.</TD></TR></TABLE>

Actually if the ecu see that the o2 isn't switching fast enough for it's liking...it m ight throw one for the primary. Then once you fix one, a new one starts switching much faster than the old(but was still good before), giving the pcm the impression that something has gone wrong with the secondary.

Also, the secondary is there as a check for catalyst efficiency, not a mixture control hence not affecting your system too lean code. You should try to get access to an actual scanner, and check your pid's to ensure things are working properly before chasing down wiring gremlins.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Justin3 &raquo;</TD></TR><TR><TD CLASS="quote">

Actually if the ecu see that the o2 isn't switching fast enough for it's liking...it m ight throw one for the primary. Then once you fix one, a new one starts switching much faster than the old(but was still good before), giving the pcm the impression that something has gone wrong with the secondary.

Also, the secondary is there as a check for catalyst efficiency, not a mixture control hence not affecting your system too lean code. You should try to get access to an actual scanner, and check your pid's to ensure things are working properly before chasing down wiring gremlins. </TD></TR></TABLE>

That's actually the reason when I get a code for one, I replace both at the same time.

 

Ok, well i still have the primary 02 sensor, would that work for the 2nd 02 since the wiring is the same for both, i know im probably going to get bashed for this but im running a T1R testpipe, ( got a good deal on the Full T1R exhaust), but this check engine light was on b4 i installed these, so my question is could i use the old Primary 02 sensor for the secondary... Thanks

 

just to help narrow it down it seems to only do it when its warm... Thanks

 

ok so ive been thinking about this now... i thought a while back i was told when using my testpipe that all i have to do its ziptie it to the shift linkage bar next to the testpipe and the 02 sensor wouldnt throw a code, now im seeing that this is not the case, i need to wrap it with tin foil, or use the defouler trick, could this be why i am getting both of these CEL codes, b/c im pretty sure that this is the reason that im getting the high voltage code, but im not to sure about the circuit malfunction code, if this is why you believe im getting these codes, not only will ill fell like a dumb ***, but ill be greatful that i dont have to buy another 02 sensor... Thanks for all the help

 

that may be the reason whey you are getting the secondary O2 code. the fouler trick works, the tin foil trick is hit/miss at best.
Best bet would be to get an O2 simulator (or build one). For $5-10 at radioshack it will never die like an O2 will.

 

Yea, im going to try the tinfoil trick for now, and hopefully that works to hold me over til i can get home and have a bung welded into the testpipe... hopefully this is why my car has been drinking gas like crazy... Thanks to all for all the help.