SES Code

[whitedragon551]

Have a malfunction on bank 1 sensor 1 had no reading which is the O2 sensor that goes into the exhaust manifold. Happens to be the sensor that was unplugged to change my valve cover gasket. A mechanic happened to be there when I was and I was told if it never set a SES light off before that it probably was plugged in when the car was in accessory or on. Once it hits 3 failures it sets off the light.

How should I go about trouble shooting? I had the code cleared and it came back on the 4th startup.

[Towncivilian]

What is the exact engine code?

[whitedragon551]

What is the exact engine code?

I thought the guy said P0143. http://www.obd-codes.com/p0134

That was for the left wiring connector that I sprayed with electronic cleaner.

According to that link I may have multiple symptoms. Only symptom I have is bad gas mileage and an SES light. I cant tell if its because I was used to getting 25+ city and 30+ highway. Engine runs perfect, no stutters, no RPM fluctuations, nice steady idle, nice acceleration, no black smoke.

Wiring looks fresh. Had a mechanic look at it and thought it was new. There is no frayed wires. All wires have a solid connection. None of them appear to be loose. No holes in the exhaust. No issues with anything else electronically or mechanically so I assume this rules out PCM failure.

[Towncivilian]

Was there any corrosion or water in the oxygen sensor connector?

Should you end up needing to replace the O2 sensor, I suggest this Beck/Arnley sensor from RockAuto. Be sure to use a 5% discount code if you decide to order it.

[whitedragon551]

Was there any corrosion or water in the oxygen sensor connector?

Should you end up needing to replace the O2 sensor, I suggest this Beck/Arnley sensor from RockAuto. Be sure to use a 5% discount code if you decide to order it.

Absolutely none. I think it may be a fuse. Is that possible? The mechanic I spoke with said that if it has never set the SES light off before and I unplugged it that it may set it off if I had the car in anything but the off position. He said chances are I could clear it and it would quit.

If I need to replace it I will need it by this weekend so I will have to get it locally.

I assume I can just grab the old one with a pair of vice grips and unscrew it and put the new one in?

[Towncivilian]

If a fuse was blown, I would expect more SES codes.

Have you tried disconnecting the negative battery terminal to see if the code disappears?

Is there Advance Auto Parts in your area? If so, you can get this Bosch direct-fit OE-type O2 sensor for $45.99 before tax if you order online using discount code VISA then pick-up in store. Bosch is the original part supplier for the oxygen sensors on R50s.

Vise grips may work; if not, you'll need a 22mm or 7/8" oxygen sensor socket or try a wrench.

[whitedragon551]

At this point I will assume its faulty. Another code popped up today. P1148 is a closed Loop-B1. I assume by swapping the O2 sensor this will take care of itself.

[Towncivilian]

Yep, replace the sensor and you'll be good to go.

[whitedragon551]

Yep, replace the sensor and you'll be good to go.

Ok so perhaps you can offer some insite. Why would cleaning the contacts cause this issue? Is it possible the cleaner wasnt dissolved 100% and caused damage?

How would I double verify that the O2 sensor is infact bad? Should I check the connection with a DMM from the harness side while the car is on and check for a voltage?

[Towncivilian]

See page EC-191 of the factory service manual for the diagnostic procedure.

[whitedragon551]

Auto Value was going to price match Advanced Auto Parts since the closest one to me was out of stock and couldnt get one for 3 days. They were out at Auto Value with the Bosch sensor as well so they price matched an NGK O2 sensor for me and just substituted it. So far it hasnt come back on.

[Towncivilian]

Great! NGK/NTK make great parts as well, so you should be set.