OBD-II P0136 (O2 Sensor Bank 1 Sensor 2)

Status
Not open for further replies.
Joined
Apr 17, 2006
Messages
19,528
Location
Lake Forest, CA
My friend 2003 Ford Explorer had check engine light for some time, I plugged in the OBD-II code reader and it showed P0136 (O2 Sensor Bank 1 Sensor 2).

My question is O2 Sensor 2 is the pre-cat or post-cat ?

TIA

PS obd-codes.com states that a P0136 code refers to the second oxygen sensor on Bank 1
 
Last edited:
Thanks.
The SUV is 12 years old and more than 150k miles, I think it has original O2 sensors, Cat(s) and muffler(s). Should he replace both Post-Cat sensors ? Or replace all 4 O2 sensors, Pre and Post-Cat, because they are fairly cheap at around $25/ea at Rockauto ?
 
Since I don't have correct tool(s) and time to replace the O2 Sensor(s) and neither does he, so he will buy parts and take it to a trusted mechanic.

Rockauto has Bosch and Denso O2 sensor for about $24-25/ea, normally I would replace only part(s) that failed, but he doesn't have time to take his SUV to shop several time for other sensors that why I think replace all 4 sensors makes sense for him.

You guys think Motorcraft O2 sensor is better than either Bosch or Denso ? I think my friend may keep the Explorer for 2-3 years only, neither Bosch or Denso will lasted 3-4 years ?
 
Originally Posted By: HTSS_TR
Since I don't have correct tool(s) and time to replace the O2 Sensor(s) and neither does he, so he will buy parts and take it to a trusted mechanic.

Rockauto has Bosch and Denso O2 sensor for about $24-25/ea, normally I would replace only part(s) that failed, but he doesn't have time to take his SUV to shop several time for other sensors that why I think replace all 4 sensors makes sense for him.

You guys think Motorcraft O2 sensor is better than either Bosch or Denso ? I think my friend may keep the Explorer for 2-3 years only, neither Bosch or Denso will lasted 3-4 years ?



There MAY not be anything wrong with them
Bosch would be appropriate on a German vehicle
Denso/NTK would be appropriate on a Japanese vehicle

...Not on a Ford

You don't want to [censored] around with Emissions equipment, as many new words will be learned, and hair lost from head.

meme4848087457_zpsg6h19d7g.jpg
 
On a Ford the OEM sensors may be BOSCH anyway. Ford has an extensive history with Bosch on sensors and electronics FWIW.
 
Originally Posted By: HTSS_TR
Since I don't have correct tool(s) and time to replace the O2 Sensor(s) and neither does he, so he will buy parts and take it to a trusted mechanic.


If accessible, all you need is a 7/8" wrench. Do it stone cold- 90% of the time the come right out.
 
Originally Posted By: HTSS_TR
Since I don't have correct tool(s) and time to replace the O2 Sensor(s) and neither does he, so he will buy parts and take it to a trusted mechanic.

Rockauto has Bosch and Denso O2 sensor for about $24-25/ea, normally I would replace only part(s) that failed, but he doesn't have time to take his SUV to shop several time for other sensors that why I think replace all 4 sensors makes sense for him.

You guys think Motorcraft O2 sensor is better than either Bosch or Denso ? I think my friend may keep the Explorer for 2-3 years only, neither Bosch or Denso will lasted 3-4 years ?


If the Bosch are direct fit they are probably the OE manufacturer for Ford anyway.
Don't believe stuff about only these for Japanese and these for Germans and those for Fords its absolute nonsense.
We have used Bosch, Walker, AC Delco, Denso, NTK, BERU, in all sorts of cars and never had any problems. All are maintaining nice fuel trims over many years and miles.

Infiniti 3.5 running Walker wide bands
VW V6 running Denso
GM 3800 running Walker another running Bosch
GM 3400 running NTK
VW Bettle running AC Delco Another running Denso
Honda 3.5 running AC Delco, another on Denso and yet another on Bosch all wide band
Toyota 3.0 V6 on Bosch another on NTK
GM 2.8 running an NOS Beru from 1999.

Not a PO420 or fuel trim issue in the bunch. All have 80K+ on them. If there was anything to that theory almost all of them should be having problems.

The only problems i ever had was with a universal, i refuse to use them.
Keep the rear O2's as long as they don't throw a code, they are just cat monitors. In an older vehicle a slightly lazy monitor can be helpful in keeping PO420/430 away.

Edit: I should mention i have also used Standard and a few others all without problems.
Many times the O2 get blamed for underlying issues. The most common real O2 failure is in the heater circuit.
 
Last edited:
I had the same issue on my Nitro. The Nitro uses the same sensor for all four positions. I decided to buy two new sensors. I pulled the bad post cat sensor and threw it away. Then I pulled the old good pre cat sensor from the same side, and installed it in the post car position. Then I put the new sensors in both pre cat positions. The pre cat sensors are doing all the adjustments. The post cat sensors are just verifying that the cats are working correctly.
 
Originally Posted By: Trav
If the Bosch are direct fit they are probably the OE manufacturer for Ford anyway.
Don't believe stuff about only these for Japanese and these for Germans and those for Fords its absolute nonsense.
We have used Bosch, Walker, AC Delco, Denso, NTK, BERU, in all sorts of cars and never had any problems. All are maintaining nice fuel trims over many years and miles.

According to Rockauto, Bosch is "OE Style Oxygen Sensor", I think it is a direct fit.

But there is some confusing about pre and post Cat sensors. Bosch and Denso have different sensors part numbers for the rears.

Bosch has 1 sensor Part# 15716 for Upstream and
Downstream Left, another sensor Part# 15717 for Downstream Right.

Denso has 1 sensor Part# 2344046 for Upstream, 1 sensor Part# 2344610 for Downstream Left and 1 sensor Part# 2344609 for Downstream Right. All these sensors are for Engine VIN K, What is this Engine VIN K ?

Originally Posted By: Trav
The only problems i ever had was with a universal, i refuse to use them.
Keep the rear O2's as long as they don't throw a code, they are just cat monitors. In an older vehicle a slightly lazy monitor can be helpful in keeping PO420/430 away.

Edit: I should mention i have also used Standard and a few others all without problems.
Many times the O2 get blamed for underlying issues. The most common real O2 failure is in the heater circuit.

I have no idea what is the O2 heater circuit and where it is located.

As of now I think he just needs to replace O2 sensor(s) and hope that the CEL will not come bcak for few years.

Originally Posted By: cbear
I had the same issue on my Nitro. The Nitro uses the same sensor for all four positions. I decided to buy two new sensors. I pulled the bad post cat sensor and threw it away. Then I pulled the old good pre cat sensor from the same side, and installed it in the post car position. Then I put the new sensors in both pre cat positions. The pre cat sensors are doing all the adjustments. The post cat sensors are just verifying that thee cats are working correctly.


Good recommendation here.

Since the failure is Passenger Rear (Downstream Right) and it is a unique sensor (probably longer wire length), I think replacing 2 pre-cat sensors and right post-cat will be okay, keep the 2 good pre-cat sensors in case the Driver Rear (Downstream Left) gives CEL in near future.

Or just replace Passenger Rear (Downstream Right) for now and worrying about other sensors when CEL is on.

If this was my SUV I would prefer former option to save time(and possibly labor cost), but it isn't and my friend may not understand why replace O2 sensors that didn't give CEL.

Thank you all for your inputs and advices.

Parker is ahead of Seattle by a score of 13-0.
 
Last edited:
Status
Not open for further replies.
Back
Top