O2 sensor replacement
- Thread starter cretecrawler
- Start date
No... On "Cleaning" O2 Sensors...
Have a Look Here...
Ask your Friend WHY he either wants to "Clean Them...or Replace Them". If he wants to replace them because he is getting "O2 Sensor Codes"... Tell him that the O2 Sensors are actually working properly when they report issues of incomplete combustion or "Left-Over O2". Explain that this is precisely what they are meant to be doing.
Tell him that ordinary Oxygen Sensors use a Thin Slice of Cubic Zirconia held inside of a Protective Cage and they meter the Exhaust Stream while sampling for the presence of Oxygen that SHOULD have been almost completely consumed (Burned) during the Internal Combustion Events occurring within each Engine Cylinder 4 Stroke Cycle.
If the O2 Sensors find a certain percentage left over in excess AFTER they enter Closed Loop... Then something is not right: Vacuum Leaks, Failing EFIs, Failing Fuel Pump Pressure... such things can all contribute to the presence having of TOO Much Oxygen getting into the Engine Cylinders during combustion events and LEAN out the Fuel to Air Ratios.
These devices strictly measure the presence of Oxygen in EXCESS... NOT Fuel in EXCESS. Tell him the 'One Up Front' measures for Excess O2 BEFORE the Exhaust Stream gets into the Catalytic Convert and that the OTHER O2 Sensor measures the presence of Oxygen left over AFTER the Catalytic Converter has supposedly Treated the Exhaust By-Products and "Cooked" them free of N2O and other Noxious Vapors. He needs to find out WHY these conditions exist due to those other causes and events being "Out of Whack".
Have a Look Here...
Ask your Friend WHY he either wants to "Clean Them...or Replace Them". If he wants to replace them because he is getting "O2 Sensor Codes"... Tell him that the O2 Sensors are actually working properly when they report issues of incomplete combustion or "Left-Over O2". Explain that this is precisely what they are meant to be doing.
Tell him that ordinary Oxygen Sensors use a Thin Slice of Cubic Zirconia held inside of a Protective Cage and they meter the Exhaust Stream while sampling for the presence of Oxygen that SHOULD have been almost completely consumed (Burned) during the Internal Combustion Events occurring within each Engine Cylinder 4 Stroke Cycle.
If the O2 Sensors find a certain percentage left over in excess AFTER they enter Closed Loop... Then something is not right: Vacuum Leaks, Failing EFIs, Failing Fuel Pump Pressure... such things can all contribute to the presence having of TOO Much Oxygen getting into the Engine Cylinders during combustion events and LEAN out the Fuel to Air Ratios.
These devices strictly measure the presence of Oxygen in EXCESS... NOT Fuel in EXCESS. Tell him the 'One Up Front' measures for Excess O2 BEFORE the Exhaust Stream gets into the Catalytic Convert and that the OTHER O2 Sensor measures the presence of Oxygen left over AFTER the Catalytic Converter has supposedly Treated the Exhaust By-Products and "Cooked" them free of N2O and other Noxious Vapors. He needs to find out WHY these conditions exist due to those other causes and events being "Out of Whack".
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Right... The MAF is a central to the performance on the later model TBs & Envoys to this arrangement because it actually Weighs the Air passing by the Heated Resistor Wire inside of the Unit and works in concert with the adjacent IAT (Inlet Air Temperature) Sensor to recognize how much denser the air passing through it can get in Winter vs. in Summer while handling and adjusting to changes in Barometric Pressure at any given Altitude.
Strangely... Everything about the Modern Fuel Injected Engines isn't about Fuel... but about ensuring that the PCM knows precisely how much Air is passing though the Motor to achieve the 14.7:1 Air to Fuel Ratio at All Times. Mention to your Pal that he should use the CRC MAF Part# CRC 05110 Solvent vs. using any Brake-Kleener Solvent. Also check just how well the Connectors are attached and look closely for conditions showing insulation cracks or wire breaks (Rodent Damage) ... just to be sure:
Strangely... Everything about the Modern Fuel Injected Engines isn't about Fuel... but about ensuring that the PCM knows precisely how much Air is passing though the Motor to achieve the 14.7:1 Air to Fuel Ratio at All Times. Mention to your Pal that he should use the CRC MAF Part# CRC 05110 Solvent vs. using any Brake-Kleener Solvent. Also check just how well the Connectors are attached and look closely for conditions showing insulation cracks or wire breaks (Rodent Damage) ... just to be sure:
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Yes tried to get some maf cleaner from local stores and it seems to be out of stock from everywhere I tried. Used the alternative choice of crc electronics cleaner but saw no difference in the cleanliness of the maf sensor.
To give a little background on the running of the vehicle, have been experiencing a rather strange occurrence for a while now.
When coming to a stop while still in gear, the engine feels like a cylinder miss. Knock it into neutral and goose it a little and it clears up. Same scenario but shift to neutral b4 stopping and it doesn't happen.
Some other possible causes:
(1) Old, High Mileage, Worn or Mis-Gapped (as in Non-OEM Factory Gapping) of the Spark Plugs. Use ONLY the book recommended Part Number of the ACDelco Plugs here.
(2) Dirty MAF? Then the Throttle Body probably requires a Good Cleaning, too. R&R the TB & Carb Spray and Wipe it down thoroughly, inside and out. Then give it a "Shake Test" to look for signs of any Broken Gears Rattling around inside of the Sealed Electric Drive Motor. Remove the Negative (-) Battery Cable for 30 Minutes after this service to help with the Re-Learn necessary by the Throttle Body after Cleaning.
(3) Dirty CPAS (Camshaft Position Actuator Sensor). Pull the (3) Power Steering Reservoir Bolts, R&R the CPAS and Clean the Screens of GUNK and Debris. ALSO... Change the Oil and Oil Filter at the Same Time.
(4) Check for any High Mis-Fire Counts in the PCM to dial in on any particular Cylinder Codes P0301-P0306 or for the presence of General P0300 indicating possible Vacuum Leaks around the Intake Manifold or Weak EFI Performances Leaning out the AFR on a particular Cylinder. Tighten those IM Flange Fasteners NO MORE than 89 Inch Pounds to re-seal the Three Rubber Intake Port Grommet "O"Rings. These tend to flatten out over time and lose their ability to keep out un-regulated Air.
(5) The Easiest Way to determine if the Intake Manifold is Loose is to look for Oil Leaking out from the Lower IM Flange. That is Motor Oil getting ingested into the IM via the Resonator Box Rubber Elbow through the Throttle Body. It can accumulate enough down inside in the bottom interior of the IM to drain out onto the Driver's Side of the Engine Block along the IM Flange if it gets loose. This means that either the IM needs 'snugging up'...or the quite difficult job of the IM R&R and then the replacement of those Three Rubber "O" Ring Grommets with a Brand New Set.
(1) Old, High Mileage, Worn or Mis-Gapped (as in Non-OEM Factory Gapping) of the Spark Plugs. Use ONLY the book recommended Part Number of the ACDelco Plugs here.
(2) Dirty MAF? Then the Throttle Body probably requires a Good Cleaning, too. R&R the TB & Carb Spray and Wipe it down thoroughly, inside and out. Then give it a "Shake Test" to look for signs of any Broken Gears Rattling around inside of the Sealed Electric Drive Motor. Remove the Negative (-) Battery Cable for 30 Minutes after this service to help with the Re-Learn necessary by the Throttle Body after Cleaning.
(3) Dirty CPAS (Camshaft Position Actuator Sensor). Pull the (3) Power Steering Reservoir Bolts, R&R the CPAS and Clean the Screens of GUNK and Debris. ALSO... Change the Oil and Oil Filter at the Same Time.
(4) Check for any High Mis-Fire Counts in the PCM to dial in on any particular Cylinder Codes P0301-P0306 or for the presence of General P0300 indicating possible Vacuum Leaks around the Intake Manifold or Weak EFI Performances Leaning out the AFR on a particular Cylinder. Tighten those IM Flange Fasteners NO MORE than 89 Inch Pounds to re-seal the Three Rubber Intake Port Grommet "O"Rings. These tend to flatten out over time and lose their ability to keep out un-regulated Air.
(5) The Easiest Way to determine if the Intake Manifold is Loose is to look for Oil Leaking out from the Lower IM Flange. That is Motor Oil getting ingested into the IM via the Resonator Box Rubber Elbow through the Throttle Body. It can accumulate enough down inside in the bottom interior of the IM to drain out onto the Driver's Side of the Engine Block along the IM Flange if it gets loose. This means that either the IM needs 'snugging up'...or the quite difficult job of the IM R&R and then the replacement of those Three Rubber "O" Ring Grommets with a Brand New Set.
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