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RiteFlo by acs

RiteFlo by acs. RiteFlo by acs. OBDII Training Module. Ground To Cover. What does a catalytic converter do? What is OBDII? Why do OBDII converters fail? What’s important in replacing them?. What’s All The Fuss About OBDII?. What Does A Catalytic Converter Do?. Three Way Converter (TWC).

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RiteFlo by acs

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  1. RiteFlo by acs RiteFlo by acs OBDII Training Module

  2. Ground To Cover • What does a catalytic converter do? • What is OBDII? • Why do OBDII converters fail? • What’s important in replacing them? What’s All The Fuss About OBDII?

  3. What Does A Catalytic Converter Do?

  4. Three Way Converter (TWC) Harmful Gases Converted

  5. What Is A Catalytic Converter? • Ceramic or metal substrate • Substrate coated with platinum group metals (PGM) – very expensive • Platinum, palladium, rhodium • Insulation wrapped around substrate • Enclosed in stainless steel container Located Between Engine And Muffler

  6. How Does It Work? • Exhaust gases pass through coated substrate • Catalyst on substrate reacts with harmful gases • Harmful gases converted to CO2, H2O, N2 Toxic Gases Converted To Common Gases

  7. Combustion Process • Perfect combustion • Gasoline + O2→ CO2 + H2O • Harmful side-effect gases • CO – carbon monoxide • HC – unburnt fuel • NO and NO2 (NOX) – nitrogen oxides Imperfect Combustion Products Result

  8. Why Are They Harmful? • CO • Poisonous, colorless, odorless • HC • Contribute to ground-level ozone, smog • May cause cancer • NOX • Contributes to smog, acid rain • Can cause irritation to lungs Health Problems May Result

  9. Chemical Reactions • Oxidation reaction • CO + O2→ CO2 • Gasoline + O2 → CO2 + H2O • Reduction reaction • NOX → O2+ N2 Harmful Gases Converted By Catalyst

  10. What is OBDII?

  11. Engine Control For Emissions Other Sensors Engine Control Module (ECM) OBDII Diagnostics MIL Fuel Injectors Engine Catalytic Converter Oxygen Sensors Engine Control And Emissions Monitoring

  12. How Does It Work? • 1996 and newer cars (some 94-95) • Electronic fuel and ignition control • O2 sensors before, after converter • ECM adjusts air/fuel ratio, ignition • OBDII monitors for emissions Controls To Reduce Emissions

  13. Oxygen Sensors • One ahead of converter signals ECM to optimize air/fuel ratio • One after converter measures emissions reduction performance • MIL turns on if ECM can’t achieve Sensor Feedback For Engine/Converter

  14. How Do I Tell If OBDII? Vehicle Emission Nameplate Under Hood

  15. Why Do OBDII Converters Fail?

  16. Rich Air/Fuel Ratio • Converter overheats and melts • Causes • Improper fuel mixture • Improper timing • Faulty spark plugs or wires • Defective fuel injector • Faulty oxygen sensor Engine Tuning Vital To Converter Life

  17. Carbon Deposits • Carbon on substrate fouls function • Causes • Oil or antifreeze in exhaust stream • Look for worn piston rings, valve seals or failed gaskets Maintenance Problems Foul Converter

  18. Other Causes • Leaded fuels • Will poison catalyst and render it useless • Catalyst breakage • Look for dents or broken hangers Never Use Leaded Fuels

  19. Failed Oxygen Sensors • Same contaminants as for converters will impair function • Deposit on probe will sense lean, ECM enriches, problem gets worse Check Sensor Before Replacing Converter

  20. What’s Important In Replacing Them?

  21. What EPA Regulations Say • Regulator specifies performance not design • “good enough that the catalyst monitor will not detect a problem for the required 25,000 mile performance period” (EPA letter Aug. 2, 2000) • Inadequate catalyst may initially turn MIL off but have it come on again after curing “OBDII Compliant” Not The Whole Story

  22. Fix The Root Cause • OEM converters should last life of car • Address the maintenance issue first • Check the oxygen sensors • Replacement converter must have adequate PGM loading Don’t Compromise And Risk A Comeback

  23. Replacing The Converter • Use scan tool and address all faults • Replace each failed converter • Maintain oxygen sensor locations • Installation must be leak free • Reset fault codes and road test vehicle Use Converter Recommended For Vehicle

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