Which side of the moter is the right side

what engine is there, , size, displacement in liters or CUInches.
3.8L V6?
p-0135 is a uSA federal code, all P0xxx are.
P1xxx are care makers owned codes, means do not read lies on the internet about, p1,p2,and codes only read your service manual
learn that bad heaters are to be fixed first 02 replaced or wires melte there..
HO2S-11 Heater Circuit (Bank 1, Sensor 1) bad O2, front of CAT sensor bank 1,
aka. upstream.
bank one is cylinder #1 bank side.
#1 cyl is the most front cylinder on all v6 or v8.
all this is me reading your service manual to you.
p1132
Lack of HO2S-11 Switching, HO2S Signal High Input this fails because heater is dead. so is moot here, later yes now no.
0135 first.

p1151

Lack of HO2S-21 Switching, HO2S Signal Low Input bank 2, sensor 1. (may be caused by above otherS.)

H-hear, O 2 means oxygen sensors
11 is bank1 senser.
12 B1S2
21 b2s1
22 B2S2
SEE?

Check which side of your engine has cylinder #1. That side is bank 1. Bank 2 is the side opposite of bank 1. So bank 2 is not always passenger side. And since you seem to have extra O2 sensors, I would replace the other upstream and see what happens. Also the mass air sensor can give a trouble code issue to the upstream 02 sensors. Good luck. I've struggled thru this myself.

P1151 is indicating an problem with the upstream O2 Sensor on Bank 2. Bank 2 is the even cylinders side O2 sensor. The P0175 code indicates a rich condition in Bank 2 exhaust. This indication, if by itself, would indicate a faulty MAF Sensor or a vacuum leak, but since you already have the P1151, change the Bank 2 O2 sensor first and most likely both codes will clear.

Hope this helps you or future parties of intrest. P1131 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1 P1151 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 2 I would get under your stang and gently clean outside portion of o2 sensors using a scotch brite. Also if you have so dielectric grease pull electrical connections to o2 sensors clean them and add grease. These trick eliminated the o2 sensor OBD1 codes on my 1987 Ford mustang gt

Hello! Both faults are pointing at the same Oxygen Sensor...Upstream Bank 2...Meaning in the exhaust header before the Cat. converter on the right side of the engine...O2 sensors generally cause a P-code as an effect rather than a cause...But in this instance it's a defective O2 Sensor...Replace...

Guru.....Saailer

I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867

First, I wouldn't let that guy work on your car. P1133 is "O2 Sensor Slow Response - Sensor 1" Anybody that has been in the auto repair business for more than a week should know that Sensor 1 is ALLWAYS the FRONT sensor.

Note: O2 sensor codes do not necessarily mean that an O2 sensor needs to be replaced. Most O2 Sensor codes are caused by something other than the O2 Sensor itself. (there are several different possible O2 Sensor codes for your car. P0131, P0132, P0133, P0134, P0138, P0171, P0172, P1133, P1134)

The most likely cause of DTC (Diagnostic TroubleCode) P1133 is contamination of the O2 Sensor. Replacing a contaminated O2 Sensor without repairing the source of the contamination will only result in a repeat repair. It could be caused by bad fuel, improper use of RTV sealant, engine oil or engine coolant. I have seen this caused many times by engine oil leaks that run down the exhaust and clog the holes in the side of the sensor shield. (The sensor must "breathe" to work properly)

Then on the other hand, if your vehicle has a lot of miles on it, the sensor could be just chemically worn out. In any case, the FRONT sensor is the one that is setting the code.

Lack of upstream heated O2 sensor bank 1 & bank 2. I would first check for broken or corroded wires to both upstream O2 sensors. If no apparent bad wires O2 sensors are bad.

those two codes are for the o2 sensors. both are the upstream sensors on the front and rear banks. so they are desinagted bank 1 sensor 1 and bank 2 sensor 1. them most common cause for this is faulty o2sensors , bad gas and of a poor running engine. so if your car runs good (no misfire) and gas is ok then replace the o2sensor witch is the very most common cause.

Your auto has four O2 sensors. Two upstream and two downstream; With two banks. Bank 1, sensor 1...and bank 2, sensor 1 are the two upstream (exhaust manifold before the catalytic). Bank 1, sensor 2 and bank 2, sensor 2 (other side of catalytic)

Code 1131= upstream; bank 1..sensor 1
Code 1151= upstream; bank 2..sensor 1
Code P0136 (generic code) bank 1..sensor 2 (questionable)

I wouldn't spend the money to purchase 3 sensors. Highly unlikely all three are bad; Cost is about $40/ ea.
Since there isn't a code for the cat's themselves, I would suspect the O2 circuit is malfunctioning. The rough idle is another clue.


Take an ohmmeter set it on X10 scale and measure the resistance from engine to body and body to negative post on battery terminal. You should read zero ohms (full needle deflection). If you do go buy two upstream O2 sensors. If you read
open or a high resistance run two straps from eng. to body...and body to neg.batt. post.

FixYaWIZ................saailer



I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867

Well, Bank 1 is the passenger side of the vehicle. Are you replacing upstream or downstream 02 sensor?

The upstream is in the exhaust manifold. The downstream is further down in the exhaust pipe. Upstream would be designated by the code HO2S1- B1 and the downstream would be indicated HO2S2-B1.

In either case, you basically unplug the wiring connector, use a 7/8 wrench (or an O2 sensor socket which has a groove cut in the side to allow the wiring to not be pinched) and loosen the sensor and install the new one (with anti-seize on the threads) and plug the connector in.

The upstream sensor is pretty easy- the downstream can be a little more difficult, but is not too bad.

Hope this is helpful!!

Nissan Scope Technician- 10+ years experience in Nissan dealership.