Wednesday, 3 April 2019



Exhaust Pipe with perfect combustion will discharge
condensed Water at the Tail Pipe. 💯% Perfect

The Vehicle exhaust system comprises of Exhaust Manifold, Warm Up Three Way Catalyst (WU TWC), Three Way Catalyst (TWC), Air-Fuel Ratio Sensor  (A/FS), Heated Oxygen Sensor (HO2S), Muffler, Flexible Joints, Tail Pipe, Exhaust  Suspension Rubber and Anchor, Exhaust Packing and Seal, e.t.c.
The exhaust system is important in the operation schematic of an Automobile. Why so? Just consider yourself eating and having your Anus blocked; yeah I mean the Anus. Hence all intake of Fuel and Air, stochiometrically balanced at 1:14.7 will all produce Carbon Dioxide, Water vapour and some other Oxides, and no source of exhaust for this by-product. The engine practically becomes plugged and blocked and chokes up.

A blocked catalyst can be Diagnosed before becoming critical or affecting Engine Performance. The Engine with a Blocked Catalyst will Start up and run fine at cold start up and at warm-up condition it will start loosing power because of the build-up of Exhaust gas in the Exhaust Manifold with no exit channel due to the blocked Catalyst. Hence the Engine will not Revv properly when the Accelerator Pedal is depressed neither will it Accelerate properly when moving with this condition on an Highway. This condition sometimes camouflages as a faulty Transmission System but on Diagnosis with a Scan tool you will see Diagnostic Trouble Code P0430 (Catalytic Converter bellow Performance Threshold Bank 1) and P0420 (Catalytic Converter bellow Performance Threshold Bank 2), and not P07** (Generic Transmission code designation)
A further Test would be a Exhaust Manifold Back Pressure Test. This involves loosening the Upstream Oxygen Sensor (Air-Fuel Ratio Sensor)and hooking up a Pressure Gauge to test the build up of Exhaust Pressure. The indication will be an increasing pressure that isn't steady but increasing till it Maxs out; values and pressure reading should be steady if the Exhaust passage is through and not Blocked.
With fancy Test tool as the Exhaust Back Pressure Tester, simply loose the Upstream Oxygen Sensor (Air-Fuel Ratio Sensor) and be ready for excessive noise as you drive the car around....I know it could be very noisy so be careful and take caution.
Finally physical inspection of the Catalyst Pot will reveal a Blocked passage or a system packed with wire Mesh...Yes!!! This is terrible and wicked of Technicians and Mechanic and Vehicle Dealer. Don't kill the Engine, simply leave the Catalyst missing till you have funds to replace such with the OEM parts specifications.

Air/Fuel Ratio Sensor bolted to a Blocked Catalyst Pot on an Intake Manifold (Toyota 2AZ-FE)

Wire mesh particles poured out of a Blocked Catalyst Pot. Replacing a Catalyst with Wire Mesh totally alters the Engine Performance.

I hope you've learnt something new, some Technicians even call the Catalyst "INDOMIE" . lol. Your missing Catalyst will increase your Fuel consumption and reduce the value of your MPG (Miles Per Gallon). Let's Diagnose for you today and fix up your vehicle to manufacturer's specifications.

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