Got a 92 Nissan pickup truck with 120k miles. The intermediate exhaust pipe, just behind the cat has corroded through, so I'll be replacing that and the worn muffler as well. With this many miles and age, should I replace the cat while I'm there? I have noticed a slight decrease in fuel mileage/power over the last few years, but nothing significant. I greatly appreciate any wisdom you might be able to throw my way! -Frank
Should I replace my catalytic convertor?
Aug 26, 2003
5 Replies
I agree. If the O2 sensor has never been changed, then it's certainly time.
I've heard that changing the O2 sensor every 30-40k miles will help keep it running more efficiently.
| check your oxygen sensor to make sure it is working
Isn't oxygen supposed to have been converted to CO2, in engine 's combustion chamber ?
In the perfect world, yes. In reality only some of it gets converted into CO2. The converter takes the byproducts of combustion and converts the NOx to Nitrogen and Oxygen and uses the excess Oxygen to combine with the HC to make CO2 and H2O.
| In reality only some of it gets converted into CO2.
Doesn't a CO sensor ( fitted onto exhaust manifold, e.g. on my Honda F20A engine ) tell engine's microprocessor to inject more petrol into engine, if CO % is low i.e. oxygen content of air intake is not fully used up ?
There is no CO sensor on any car.
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