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Discussion Starter · #1 ·
Hi, ive had an error code for a while which i've kinda ingored as i was advised it would "go away" Think its P0175 but it was definitely diagnosed as running rich on bank 2. Just wondered if anyone else has any experience of this fault code and what will cure it?
 

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hi ste,yep id the same problem,which i ignored for nearly 2 years of running poor and spending a fortune on petrol! its your oxegen/lambda sensor. most of the time they mess up if u run outa petrol and try start the car,but thats defo what you need to get;)
 

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R.I.P [The Red Zed] MG ZS 180
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This may help

P0175 OBD-II Trouble Code
Technical DescriptionSystem Too Rich (Bank 2)

What does that mean?Basically this means that an oxygen sensor in bank 2detected a rich condition (too little oxygen in the exhaust). On V6/V8/V10 engines, Bank 2 is the side of the engine that doesn't have cylinder #1.

Note: This DTC is very similar to P0172, and in fact your vehicle may show both codes at the same time.

SymptomsYou will more than likely not notice any drivability problems, although there may be symptoms such as a misfire.

CausesA code P0175 may mean that one or more of the following has happened:

The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters can cause the MAF to become dirty if the filter is over-oiled
There could be a vacuum leak.
There could be a fuel pressure or delivery problem
Possible SolutionsPossible solutions include:

Inspect all vacuum and PCV hoses, replace if necessary
Clean the MAF sensor. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
Inspect fuel lines for cracks, leaks, or pinches
Check the fuel pressure at the fuel rail
Check the fuel injectors, they may be dirty. Use fuel injector cleaner or get them professionally cleaned/replaced.
Check for an exhaust leak before the first oxygen sensor (this is unlikely to cause the problem, but it is possible)
 

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Discussion Starter · #4 · (Edited)
hi ste,yep id the same problem,which i ignored for nearly 2 years of running poor and spending a fortune on petrol! its your oxegen/lambda sensor. most of the time they mess up if u run outa petrol and try start the car,but thats defo what you need to get;)
Cheers guys, It did run out of petrol i think the day before this error code started occurring.

Last time Nigel reset my MIL for me. He noted that the volts on the the post cat lambda were way down. 0.1v and i think they should be 0.3v. So, i've bought a new post cat lambda sensor off dogsby and fitted a MIL eliminator from Jay-ZS+ hoping that might cure it. Need to get it reset again now to see if that stops it coming back on.

Oh, it's got a sports cat fitted thats the reason for the MIL eliminator kit. ECU Thinks that the CATS knackered.
 

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Had my lambda replaced, still misfires and hesitates with light on/off

Cleaned everything I can, still persists HELP
 

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P0172 or P0712 I forget, same as before sensor replaced
 

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Discussion Starter · #9 · (Edited)
Had my lambda replaced, still misfires and hesitates with light on/off

Cleaned everything I can, still persists HELP
There are 3 lambdas, 2 precat and 1 post. I dont think cleaning these things does any good, which one did you replace?

P0172 or P0712 I forget, same as before sensor replaced
Well its either one or t'other, Be sure its the correct one.

P0172 is a rich on bank 1 error code. so very similar to mine. see this for a bit more info http://www.obd-codes.com/p0172

I dont see how that would cause misfire though? you may have more than one code stored, or a separate code pending which wouldnt show on a scangauge II. You really need someone who has a laptop with OBDII sortware on it.

Oh yes, can cause misfire, apparently. although i never experienced this. Again what lamba was replaced?
 

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Hi, ive had an error code for a while which i've kinda ingored as i was advised it would "go away" Think its P0175 but it was definitely diagnosed as running rich on bank 2. Just wondered if anyone else has any experience of this fault code and what will cure it?
Thats a mk2 for ya :whistle: Chop it in for a nice mk1, ya probably even be quids in! :yup::D
 

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Front o2 sensor replaced, as didn't replaceit not sure which front one
 

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Discussion Starter · #12 ·
Thats a mk2 for ya :whistle: Chop it in for a nice mk1, ya probably even be quids in! :yup::D
True, MK2's are far from perfect but at least they dont resemble a rebadged grandads car. Dont get me wrong, i like MK1's, if it wasnt for them we wouldnt have our nicer looking MK2's would we :stir:

Front o2 sensor replaced, as didn't replaceit not sure which front one
There are 2 pre cat, may have needed both changing. I would suggest getting the volts measured from each one to see which is giving off low volts.
 

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True, MK2's are far from perfect but at least they dont resemble a rebadged grandads car. Dont get me wrong, i like MK1's, if it wasnt for them we wouldnt have our nicer looking MK2's would we :stir:
Yeah that's cleared that up, Mk2 is like me Grandad wearing Nike's , baseball cap 'n' shell suit ...it's .......Jimmy Saville! itsok :wave:
On the plus side, when the Pektron's thrown it's next tantrum, at least it'll actually look good sitting on ya drive...:confused: :D
 

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P0152 02 Sensor Circuit High Voltage (Bank 2 Sensor 1)


sorry completely wrong code, this is what i'm getting (cross referenced code with this site)
 

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R.I.P [The Red Zed] MG ZS 180
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Heres info on that code.

P0152 O2 Sensor (High Voltage)

OBD-II Trouble Code Technical Description02 Sensor Circuit High Voltage (Bank 2 Sensor 1)

What does that mean?The o2 (oxygen) sensors basically measure oxygen content in the exhaust. The PCM (powertrain control module) then uses this information to regulate fuel injector pulse. The o2 sensors are very important to proper operation of the engine. Problems with them can cause the PCM to add or take away too much fuel based on the faulty o2 sensor voltage.

A P0152 code refers to the Bank 2, sensor 1, o2 sensor. (Bank 1 would contain cylinder 1 and bank 2 is the opposite bank. Bank 2 doesn't necessarily contain cylinder 2.) "Bank 2" refers to the side of the exhaust that DOES NOT contain cylinder number 1 and "Sensor 1" indicates that it is the pre-cat sensor, or forward(first) sensor on that bank. It is a four wire sensor. The PCM supplies a ground circuit and a reference voltage of about .5 volts on another circuit. Also for the o2 heater there is a battery voltage supply wire and another ground circuit for that. The o2 sensor heater allows the o2 sensor to warm up faster, thus achieving closed loop in less time than it would normally take for the exhaust to warm the sensor up to operating temperature.

The O2 sensor varies the supplied reference voltage based on oxygen content in the exhaust. It is capable of varying from .1 to .9 volts, .1 indicating lean exhaust and .9 indicating rich exhaust. NOTE: A condensed explanation of fuel trims: If the o2 sensor indicates that the oxygen voltage reading is .9 volts or high, the PCM interprets this as a rich condition in the exhaust and as a result decreases the amount of fuel entering the engine by shortening injector "on time". The STFT (short term fuel trims) would reflect this change. The opposite would occur when the PCM sees a lean condition. The PCM would add fuel which would be indicated by a single digit positive STFT reading. On a normal engine the front o2 sensors switch rapidly back and forth two or three times per second and the STFT would shift positive and negative single digits to add and remove fuel to compensate at a similar rate. This little "dance" goes on to keep the air/fuel ratio at it's optimal level. Short term fuel trims or STFT reflect immediate changes in fuel injector "on-time" while long term fuel trims or LTFT reflect changes in fuel over a longer period of time. If your STFT or LTFT readings are in the positive double digits (ten or above), this indicates the fuel system has been adding an abnormal amount of fuel than is necessary to keep the proper air/fuel ratio. It may be overcompentsating for a vacuum leak or a stuck lean o2 sensor, etc. The opposite would be true if the fuel trim readings are in the negative double digits. It would indicate that the fuel system has been taking away excessive amounts of fuel, perhaps to compensate for leaking injectors or a stuck rich o2 sensor, etc. So when experiencing o2 related issues, reading your fuel trims can indicate what the PCM has been doing over the long term and short term with regard to fuel.

This code indicates that the o2 sensor was stuck too high or in the rich position. The PCM monitors this voltage and if it determines that the voltage is too high out of range for too long, P0152 may set.


Symptoms

Symptoms may include:

MIL (Malfunction Indicator Lamp) illumination
Engine may run very rough
Engine may be running lean or rich depending on if the o2 sensor is reading correctly or incorrectly
Lack of power
Increased fuel consumption

Causes

Potential causes of an P0152 code include:

Bad bank 2, 1 o2 sensor incorrectly reading rich condition
Engine running rich and o2 sensor
Correctly reading rich condition
Signal shorted to voltage in harness
Wiring harness damage/melted due to contact with exhaust components
Vacuum leak (make have lean codes (P0171, P0174) present with it)
Leaking injectors
Bad fuel pressure regulator
Bad PCM

Possible Solutions

If you have any lean or rich codes associated with this code, focus on fixing these first because these can cause the o2 sensor voltage readings to appear to be faulty when they are in fact only reading correctly.

So, with the engine running at operating temperature, use a scan tool to observe the Bank 2,1 o2 sensor voltage reading. Is it high? If so, look at the long term and short term fuel trim readings. The fuel trims are affected by the o2 sensors as noted above. If the LTFT reading for that bank is indicating negative double digits (PCM trying to take away fuel to compensate for problem) try inducing a vacuum leak to see if the sensor voltage then goes lean and the fuel trims increase. If the o2 sensor responds, suspect a problem with the engine, not the sensor. There may be other engine codes to help you.

If the o2 sensor reading remains high (0.9 volts or above) and won't respond then shut off engine. With KOEO (Key on engine off) disconnect the o2 sensor and look for signs of corrosion or water intrustion. Repair as necessary. The voltage reading should now be about 0.5 volts. If so, replace the o2 sensor, it's shorted internally.

If after unplugging the o2 sensor the voltage reading on the scan tool doesn't change, then suspect wiring problems. Inspect the harness and look for any melted wires or anywhere that the o2 sensor harness is making contact with the exhaust components. If you are unsure, you can check for continuity of all four wires between the sensor and the PCM with an ohmmeter. Any resistance at all indicates a problem. Repair as necessary.
 
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