mech_engr

I am getting error code P0138 which is the O2 sensor circuit high voltage (bank 1 sensor 2). I have cleared it several times and it has continued to come back following the 50-100 mi drive cycle. I have had SLP LT headers and a Borla catback for a while and the car never had O2 sensor issues until recently.
Is bank 1 the driver side? And is sensor 2, post-cat converter?

I found this: http://www.gearchatter.com/si/414203.png
Is there an electrical component (fuze,etc.) I can try replacing before replacing the O2 sensor itself?

How can I fix this P0138 error from recurring? I failed one state inspection (in Dallas) after I cleared the codes and the sensor was "not ready". I need to pass soon!

THANKS

lucky131969

Inspect the wiring. If no damage is found, replace the sensor..

rebelheart

I agree and your engine will run better also!

mech_engr

Can someone answer which O2 (bank 1 sensor 2) sensor that is? How much arey they and where to get the part? Thx

byronhunter

(bank 1 sensor 2)= Driver side, rear sensor

dougbfresh

Does he still have rear O2's with long tubes?

mech_engr

I bought the car with LT headers and I believe the rear o2 sensors are there. I think I've seen you can buy O2 simulators? I'm not opposed to doing this, but I do have to pass Texas obdII inspection.

dougbfresh

Hard to even find the sim's I hear anymore, not to mention they are illegal-just put the stock stuff back on to pass. Did this ever work or has it been throwing codes since day 1? You might be able to have the bad stuff tuned out.

0John@SDPC

Very hard to find sims. Google 'Caspers settlement'.

Follow the diagnostic steps in the link you found. How many miles are on the car? One easy way to confirm it is the sensor is to simply swap the driver and passenger rear sensors.

Where in Texas?

mech_engr

Discard what I previously said about running the rear O2 sensors. I had a finally had a chance to look under the car today and discovered these guys connected into the wiring. The connector that runs to the actual 2nd oxygen sensors is just wrapped in electrical tape and is zip tied to the sim. Previous owner had done this.

I inspected the bank 2, sensor 2 wiring side (on drivers side since the harnesses are crossed) and everything appeared fine - no corrosion, all connections intact which supports me not seeing DTC codes for this side.

The bank 1, sensor 2 wiring side (the problem one, on passenger side) is much more difficult to physically and visually access. The connector appeared to be in similar condition - no corrosion or heat damage. The molded surfaces of the sim did appear to be a bit more worn than the other side, could be some heat wear or could've just been dirty.

What is the failure rate on these sims? I'm not convinced the wiring is 100% because it is packaged so tightly and I can't see much of the harness. How can I test the female ends of these harnesses?

mech_engr

How can I test these rear oxygen sensor harnesses?

THANKS

Y2Kvert4me

The sims are not the most reliable devices, and very commonly fail.


If you still have rear sensors in place, and are running cats, I'd just connect them back up as stock, and see what happens. You may still get an occasional code...but might not.

minitech

The goal is to just pass emissions right?

You clear it and in the 50-100 mile driven area it comes back?

Why not just clear it ONE mile before the inspection?

Then have 49-100 miles to go until the thing codes again?

Y2Kvert4me

Any time you clear a code (or disconnect battery), it resets all readiness test monitors.

If you then test, instant fail, because no system monitor will test as ready...."drive car more, come back" is the usual advice.

This is the built-in safeguard against your very suggestion. You need to drive the car though those drive cycles without a code in order for the I/M tests to show ready status, and thus, to pass.

minitech

Hmm didn't know that. Well I guess it is back to handing him the registration with a folded $50 behind it.

ctsv510

you could also get a tune...more power and no more codes.