02 sensor. What is it?

"user1966" wrote: > Can someone help me? What is the O2 sensor? What does it do? > Can it be > replaced as a DIY job? > > thanks

02 sensor is normally located somewhere near your exhaust either in the exhaust itself or on the exhaust manifold. It measures the amount of C02 and carbon monoxide and that sort of thing that your engine is putting out through your exhaust system. Using this information the engine mangement computer can tell if the engine is running rich or lean and alter the of fuel/air mixture that is put into your engine accordingly to ensure that your engine is always running at peak efficiency.

I do know that they are very sensitive and can stop your engine completely. One person I knew fitted a new exhaust system to his car himself and the gasket cement that he used confused the O2 sensor and stopped the engine altogether. The ones I have seen look like they could be easily replaced by a DIY. Not that I have ever done one. You would be better asking a few more questions first I think.

Can't tell you about an Isuzu, but it was pretty easy on my Dodge Caravan, and I'm far from being a mechanic. If you've got a Trooper, I know some of those are programmed to kick on every 90k. Supposedly a screw you can move a screw in the dash to turn it off. But, maybe you're talking about a different model Isuzu...?

Wesley

Oxygen sensor... it is screwed into fittings into exhaust pipe. Newer vehicles can have three or more, located before (in down pipe, manifolds or y-pipe) and after the catalytic convertor(s).

The engine control computer reads oxygen content in the exhaust gasses and uses that (along with other readings) to compute optimum fuel mixture for max. economy, min. emissions. If the sensors are bad it gives incorrect reading and your engine will run very poorly. If you let it go for a long time the seriously bad mixtures will ruin your catalytic convertor(s) too and that gets really expensive; replacing convertors is usually not a job for a DIY'er as it frequently entails welding.

I haven't had to replace any O2 sensors, but it doesn't look to be too difficult. Spray thread penetrant on the threads and let it soak overnight... use a deep-well socket and appropriate breaker bar.

If it is really obstinant and won't loosen, use a propane torch to heat the fitting.

Most auto parts stores sell special sockets that clear the wire lead and connector for putting in a new one.

BuddyWh