Cars & Trucks Logo

Related Topics:

YILDIRIM SUNGUR Posted on Dec 10, 2012
Answered by a Fixya Expert

Trustworthy Expert Solutions

At Fixya.com, our trusted experts are meticulously vetted and possess extensive experience in their respective fields. Backed by a community of knowledgeable professionals, our platform ensures that the solutions provided are thoroughly researched and validated.

View Our Top Experts

Cod 51 means o2 sensor is bad but tell me please which o2 sensor is bad .upstream or down stream sensor

We located the mulfunction .its on o2 sensors but I am in doubt because I dont know which o2 sensor is bad downstream or up stream sensor

1 Answer

Anonymous

Level 2:

An expert who has achieved level 2 by getting 100 points

All-Star:

An expert that got 10 achievements.

MVP:

An expert that got 5 achievements.

Sergeant:

An expert that has over 500 points.

  • Expert 318 Answers
  • Posted on Dec 10, 2012
Anonymous
Expert
Level 2:

An expert who has achieved level 2 by getting 100 points

All-Star:

An expert that got 10 achievements.

MVP:

An expert that got 5 achievements.

Sergeant:

An expert that has over 500 points.

Joined: Nov 15, 2012
Answers
318
Questions
1
Helped
118295
Points
934

Oxygen sensors code sometimes produced because of some other problem, blocked exhaust or cat converter, over rice fuel supply or vacume leak in intake manifold giving a real lean mix and so o2 out of range in both casesw

5 Related Answers

SCOTT OCONNOR

  • 169 Answers
  • Posted on Aug 31, 2008

SOURCE: Upstream O2 sensor location?

That is the first sensor closest to the engine. The downstream sensor is the one behind the converter.
Good luck.
Please rate this response , and let me know if ya need more help!

Ad
motor1258

Mike Butler

  • 6674 Answers
  • Posted on Jan 11, 2009

SOURCE: 1997 Dodge Stratus V6 oxygen sensor location

Upstream, as in ahead of the converter, back toward engine. Start at converter and work your way back, should be on exhaust pipe or even on manifold.

emissionwiz

Marvin

  • 85242 Answers
  • Posted on Apr 26, 2009

SOURCE: Does my 1999 Mercury Mystique have 4 O2 Sensors or am I wrong?

the sensors before the catalytic converters are the upstream sensors, the ones after the after the catalytic converters are the down stream sensors, Ford calls them the Catalyst efficiency monitors.

Anonymous

  • 1 Answer
  • Posted on Aug 28, 2009

SOURCE: Getting PO141 trouble code when scanning! Car '03 accord, 2.4 ltr

i spoke to a honda tech , and he confirmed code p0141 on the 4cylinder model is the second sensor.

Mark Lewis

  • 105 Answers
  • Posted on Jul 18, 2010

SOURCE: 2001 elantra replaced cat o2 sensor upstream and

In reading what you've already done, I would suggest a Compression Test along with a vacuum gauge hooked up to the intake manifold. It may be that you're burning oil through your exhaust system in the catalytic converter. I've seen this with leaking or inoperative turbo-chargers. Pull all of your spark plugs, marking them as to what cylinder they went in with a Sharpie and if worn, replace them. Check the distributor cap & rotor button for wear or cross-firing. A Haynes Manual for your vehicle is available through most part stores which is truly effective for your DIYer. Bad plug wires can send unburned gases down through both O2 Sensors and the Catalyst. You may also want to check the plug wires and the coil(s). A fast way of checking plug wires is to grab all of them with your hand with the vehicle running and if you get "zapped"...you need spark plug wires. Remember, the codes you pull are just a general starting point as to where to start your diagnostics, not the exact problem itself. The computer doesn't monitor the mechanical aspect of your engine nor the fuel supply. The computer will take this as a given, so don't forget that when testing that it could be a compression problem or fuel problem, but as I first said...an oil leak fouling your exhaust system such as an inoperative EGR valve or oil leak on the exhaust side of the valve train.

I hope this Helps,

"00 Buck"

Ad

Add Your Answer

×

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

0helpful
2answers

2015 Chevy Impala 3.6 l upstream o2 sensor

You have 2 of those and also 2 downstream. You have two banks of cylinders and each one has an upstream o2 sensor and it is located in the exhaust manifold for each bank. Your scan tool should say Bank 1 or Bank 2.

The downstream sensors are after the catalytic converter.

What are the symptoms of a bad upstream O2 sensor? Sensor 1 Sensor 1 is the upstream oxygen sensor. It is the sensor that measures the oxygen content in the exhaust, providing an input to the computer, which determines how to adjust the air/fuel ratio. Sensor 1 is the sensor closest to the engine. Sensor 2 is the downstream oxygen sensor.
Mar 10, 2021

Bank 1, Sensor 1? Upstream or Downstream? - Newparts.com

https://www.google.com/search?q=2015+Chevy+Impala+3.6+upstream+o2+sensor+location

0helpful
2answers

Where is the O2sensor bank 1 at with a code of P0420. AND do I need to replace both sensors upstream and down. Or just the one that is showing up on the obd scanner.

Bank one is front side of cat. It should also tell u if it's cat 1 or cat 2. Depending on make an modle an yr. Catalyst 1 bank 2 is left cat back sensor. Catalyst 2 bank 2 is right cat back sensor. U do not have to replace upstream also. My o2 sensor Catalyst 2 bank 2 went bad. Had engine code for burning rich bank 2. Replaced tha down stream sensor an fixed problem runs better an better gas. This was in 97 gmc suburban. Idk what vehicle ur askin about. An I'm not to familiar with much about cars jus trucks an suvs.
1helpful
1answer

Where are o2 sensors location

One would need the year, make, model, and engine size to tell you exactly where they are and how many.

O2 sensors are always in the exhaust stream, either in the exhaust manifold that is attached to the engine, or in the exhaust piping after the exhaust manifold. Some models have one for each bank of the engine, and some have only one sensor to monitor oxygen content. These engine sensors that the computer uses to "fix" or adjust the air/fuel ratio are called the upstream oxygen sensors. If the car is equipped (as most are today) with an oxygen sensor after the catalytic converter, this is called a downstream oxygen sensor. They are the same and do the same thing, but the downstream sensor is only used to monitor the efficiency of the converter. The upstream sensor(s) are what the computer reads to adjust or "trim" the fuel delivery.

So some older cars have only one o2 sensor. Not far from the engine in the exhaust stream. Some newer cars with dual exhaust (2 converters) may have four o2 sensors. 1 for each bank of the engine and 1 behind each catalytic converter. A 2005 Buick Century with a 3.1L engine, for instance, has only two o2 sensors: one (upstream) in the exhaust down pipe, and one (downstream) just behind the catalytic converter.
1helpful
1answer

How many oxygen sensors are there on a 1996 ford explorer 8 cyl., 4.0 eng.

The answer depends on the type of exhaust system you have. You will have either 3 or 4 total O2 sensors on your V8. If you have single exhaust with a single catalytic converter then you will have 3 O2 sensors (2 upstream sensors & one downstream sensor - "up or down stream" meaning before of after the catalytic converter). If you have either dual exhaust and/or two catalytic converters then you have 4 O2 sensors (2 upstream & 2 downstream). If you have an MIL light (malfunction indicator light, or "check engine light") the code will indicate "front bank / bank one", which is one of the 2 upstream O2's before the catalytic converter(s), or "rear bank / bank two", which is one of the O2's after the catalytic converter(s).
0helpful
1answer

Downstream oxygen sensor location

Down stream o2 is always located after the catalytic converter,,Upstream o2 are before..The down stream o2 reads the effienciency of the converter
0helpful
2answers

OXYGEN SENSOR ID

Only way to tell is count the number of wires coming from it. You also need to know if its the right or left bank and upstream or down stream. Upstream is before cat converters and by or in exhaust manifolds, down stream is behind converters and only measures converter effeciancy.
2helpful
1answer

I have 2008 toyoya tocoma truck only getting 13 mpg. the check engine light on, had it scope out said o2 sensor open, replced sensor had light cancel but came back on. still have problem

Are you sure you replaced the right 02 sensor? Some vehicles have up to 4 02 sensors and being the ones that have a seperated duel exhaust system. You will have an 02 sensor located upstream of the catalytic converter and one down stream of the converter so make sure you replaced the right on. If you used a scanner to tell you it was an 02 sensor it should have also told you bank one or bank two which translates to drivers side or passengers side will also tell you up stream or down stream.
1helpful
2answers

Im confused my car is a toyota camry 6cyl not 4cyl and some say it has 4 o2 sensors and others say it has 2, hum, wich is it???? please help and also is there a site where it shows me like a diagram as to...

I have no diagram,but there is what they call upstream,and down stream locations.Upstream,is above the cat-converter,the down stream is below the cat-converter.This would be per-side.You have a left,and a right exhaust manifold.The exhaust pipes run from each manifold(left and right)to the catalytic converters.So you would have to have on the left side a up stream o2 sensor,above the catalytic converter.and a down stream o2 sensor,below the catalytic converter.this would also be on the right side also,this would be the total of four(4) o2 sensors.I hope this is helpful.
1helpful
2answers

Exact location of downstream O2 sensor.

Downstream O2 sensor is after (downstream) the catalitic converter on the exhaust pipe. Upstream O2 sensor is after (downstream) the engine exhaust manifold - before (upstream) the catalitic converter. Upstream O2 sensor controls air-to-fuel ratio to yield a small excess oxygen. Downstream O2 sensor assesses the catalitic converter performance.
0helpful
1answer

Installing 02 sensors

"Up-stream" means before the catalytic converters and are probably in the header pipe(s). The "down-stream" O2 sensors are behind the cats in the exhaust system, usually just behind them. Not the expert here on this particular car but there are probably 4 of these sensors. BMW exhaust systems are very tight on space, be careful tackling this job.
Not finding what you are looking for?

139 views

Ask a Question

Usually answered in minutes!

Top Cars & Trucks Experts

ZJ Limited
ZJ Limited

Level 3 Expert

17989 Answers

john h

Level 3 Expert

29494 Answers

Arnie Burke
Arnie Burke

Level 3 Expert

7339 Answers

Are you a Car and Truck Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...