Happy new year.... and I've got a P0133 error code (O2 sensor)

[TerryMason]

My check engine light popped on this weekend. I pulled the codes, and it gave me a P0133

P0133 Jeep - O2 Sensor Circuit Slow Response Bank 1 Sensor 1

I've read that this is most likely a bad O2 sensor, but could also be an exhaust leak. What do you guys think? Should I just go ahead and swap out the $70 O2 sensor and go from there, or is it possible to clean these things and test for an exhaust leak?

 

[TerryMason]

Am I right in assuming that the Bank 1 Sensor 1 unit (2 in the photo above) is considered the upstream rear sensor?

It looks like these sensors may be cheaper than I thought - Amazon has the NGK (which I believe is OEM) for under $30 shipped
http://www.amazon.com/NGK-23160-Oxygen-Sensor/dp/B001PNAQG4/

 

[superj]

i think the upstream is the two by the engine and the downstream are the ones behind hte cat.

i am not sure on jeeps but on bmws, 1,3,5 are the first set and 2,4,6 are the second set. the bank usually goes off which injector is firing, last i knew. so maybe see if two injectors fire at one time and two at another?

 

[superj]

are you talking about fig 23? i thought yours was a 2.5? those pics are for a 4.0

 

[TerryMason]

are you talking about fig 23? i thought yours was a 2.5? those pics are for a 4.0

I've got a weird Jeep. It's a 2005 Wrangler SE with an automatic. Jeep learned that the auto transmission doesn't go well with the 4 banger, so if you ordered a later TJ with an auto it automatically bumped you up to the 6. When I go to the parts store I normally just tell them I have a Wrangler Sport.

the short of it is that I've got the 4.0L


I think that you're right about the upstream = before cat and downstream = after cat. It makes sense that it would be that way.

I also found that RockAuto will specify some of it's O2 sensors as B1S1 / B1S2 / etc. Good idea on their part:
https://www.rockauto.com/catalog/x,carcode,1430906,parttype,5132

 

[jeepless in ga]

terry. replace the sensor. clean out your throttlebody as well.
run good gas and use lucas gas treatment at least every other
tank full. being a mechanic ive seen just about all the snake oil
on the market. I swear by this company and their product.
the gas treatment is outstanding.

https://www.lucasoil.com/articlelist1-14/0/LucasFuelTreatment

 

[JPNinPA]

Always go cheap fix first. I'd only get O2's from the dealer. I'd check the connection and wiring. Unless you had this apart and the exhaust leak was at the head you will not see this in bank 1 sensor 1. If you have an scan reader or odbII Bluetooth interface you could watch the switching to determine more.

BTW bank1sensor 1 is front of jeep near radiator pre mini cat within the manifold.

- Faulty Front Heated Oxygen Sensor Bank 1
- Front Heated Oxygen Sensor Bank 1 harness is open or shorted
- Front Heated Oxygen Sensor Bank 1 circuit poor electrical connection
- Inappropriate fuel pressure
- Faulty fuel injectors
- Intake air leaks may be faulty
- Exhaust gas leaks
What does this mean?


Read more: http://engine-codes.com/p0133_jeep.html#ixzz2pI838yin

 

[SteelHeadz]

Terry,

Unfortunately, cleaning the O2 sensor will not fix the issue. Once the O2 sensor shows failure , it needs to be replaced due to contamination or internal damage. Do the suggested throttle body cleaning and check it for exhaust leak if you haven't already before replacing the sensor.

 

[TerryMason]

Thanks guys. I've ordered the O2 sensor, and will clean the throttle body and look for leaks when I replace it.

 

[JPNinPA]

The following is how I find exhausts leaks:

Take your shop vac and attach the hose to the output of the vac, so it blows. Attach the funnel end on the hose and insert it up the exhaust. You may want to duct tape in place or have someone hold it. Turn the vac on and go feel for leaks. Many times you could hear them.

 

[TerryMason]

Take your shop vac and attach the hose to the output of the vac so it blows. Attach the funnel end on the hose and invert it up the exhaust. You may want to duct tape in place. Turn it on and go feel for leaks. Many times you could hear them.

Man - that's an awesome idea! Thank you.

 

[JPNinPA]

It is the only good way to blow up an engine. ;-P