HO2S FAULT CODE COMES UP BRINGING THE ENGINE MANAGMENT LIGHT ON I CAN ERASE THE CODE BUT KEEPS COMING ON WHAT WOULD THE ISSUE BE? I HAVE GOOGLED IT BUT DOESNT SAY MUCH ONLY JUST ABOUT THE OXYGEN SENSOR.

code p 0171 refers to system too lean bank 1===causes ---intake /exhaust leak---AIR system---MAF/VAF sensor/s---fuel pressure/ pump---injector/s---heated oxygen sensor (HO2S) the one in the exhaust manifold for bank 1 nearest the firewall

It won't reset or erase code by disconnecting the battery
you need a scanner able to erase code

hope it help

code p 0130 refers to the heated oxygen sensor (HO2S) 1 bank 1
code p 0139 refers to HO2S 2 bank 1 the HO2S is the ones in the exhaust manifold or pipe before the cat converter

MOST TIME LIMP MODE MEAN ECM FAILING IF YOU CANT ERASE OLD CODE AND REPROGRAM ECM. AND IT CANT RELEARN NEW PART ECM HAS A MEMORY FAULT.

P0146 pd means pending code
Pending codes and DTCs? Posted on November 12, 2010 by fcrmaster
When reading codes from your vehicle the fault code reader may show them as pending codes or normal Diagnostic Trouble Codes (DTC).
Pending codes (also known as continuous monitor codes) will be registered when an intermittent fault occurs. If that fault does not happen again after x number of start/stop cycles, the ECU will erase the code from memory. If the fault is persistent it becomes a DTC.
If you have read pending codes it is advisable to check the codes again after a week or so. If there is no apparent problem with the vehicle it is safe to erase the codes too and check back. But always make a note of any fault codes with the date and mileage of a vehicle.
If the codes read include a DTC then you need to investigate further. This you can either do yourself or advise your garage. If, again, you don't see an apparent problem (depending n the severity of the code) with the vehicle you can note the codes down and erase them. Then check again after a week or a few days depending on how often the vehicle gets used. If a repair has been made (previous owner) the DTC may just not have been reset after the repair.
The other numbers behind the code 01/06 , 02/06, 03/06 , 05/06 ,04/06 These don't mean anything . cheap code reader .
DTC P0140 HO2S Circuit Insufficient Activity Sensor 2
DTC P0146 HO2S Circuit Insufficient Activity Bank 1 Sensor 3
DTC P0171 Fuel Trim System Lean Bank 1
DTC P0174 Fuel Trim System Lean Bank 2
Sorry but this is something you should take to a qualified repair shop that has a diagnostic tool that can view sensor scan data.
Causes of lean condition trouble codes P0171 P0174 GM 5 3L

CODE PO421 CATALYST EFFICIENCY BELOW NORMAL BANK 1. POSSIBLE CAUSES AIR LEAKS AT THE EXHAUST MANIFOLD OR IN THE EXHAUST PIPE.CATALYTIC CONVERTER IS CONTAMINATED DAMAGED OR HAS FAILED.FRONT HO2S AND THE REAR HO2S IS LOOSE IN THE MOUNTING HOLE. FRONT HO2S OLDER AGED THAN THE REAR HO2S IS LAZY. FRONT HO2S OR REAR HO2S IS CONTAMINATED WITH FUEL OR MOISTURE.

the car is going into limp mode due to an engine management fault. have to check what the fault is with a code reader. if the milage is high 100,000+ could be a turbo fault (overboosting), as this will put the car into limp mode.

If the light was flashing when it came on, then it means your engine is misfiring.

A solid light can mean anything from a loose/faulty gas cap to a transmission issue.

This light comes on when the computer detects a fault of some sort in its diagnostic tests. If it keeps detecting this issue, the light will remain on. If the light turns off, then it has detected that the issue may no longer be present.

In order to find out what the exact reason was for your light, You need to have your car computer scanned to retrieve the code that the computer would have stored when the light triggered. Most garages will do this free of charge. The code will tell you what may have caused the light to initially turn on.

The best ideea is to scan your Engine Control Unit with a VAG-COM, Bosch KTS, ... diagnosis tool. If you have one of these dedicated scan tools you will find definitely the engine fault code-"P...." and the clear description of the error. Also you can try to erase this error (or these errors) from the Engine Control Unit memory. If errors are "sporadic" type you certain have permission to erase them, also for some kinds of "static" errors. Because your Engine "MIL" - Malfunction Indicator Lamp keeps coming "ON" and "OFF" you have a big good hand to clean errors from Engine Management System memory. If you don't have any diagnosis tool, you can also try something else. For check up if the engine have a proper turn, you can successively disconnect each spark plug coil from the engine wiring system, engine idle, car stationary. When you operating this you must be free of chassis ground (battery ground)!!! When you disconnect a spark plug coil and the engine speed (rpm) drops, that means this coil works properly. When one coil disconnected and engine speed (rpm) still remain unaltered, this coil (or spark plug) is out of order. First you can change only the spark plug and check up again. If no changes the coil is defective and must be replaced! My recommendation is first to change all spark plugs on the engine, and after that check up coils. Please Rate my Response! Thanks!

Hi

I see you posted this in Nov O8 and expect you might be OK.

If not you might try this.

Try disconnecting the battery + & - terminals.

Turn the ignition key several times to erase the computers memory.

Reconect the battery + terminal then - and start the car.

Your fault code, will hopefully not return.

Hope this is of help.

Good Luck !

John.