arielb1

My exhaust stinks on my 4runner. I have 110K miles manual V6, 1994 and it continually gets worse smelling. I can drive with my back window open anymore and my kids hate the smell.

Today I noticed my coolant reserviour was empty and white smoke is coming out of my truck when I started it. I had the head gasket replaced at 60K per service campaign in year 1999.

I was told I have to replace my O2 sensors since they have not been touched. Will I damage my new O2 sensors if I have a head gasket problem? Will it resolve the stinky exhaust? Smells like exhaust not rotten eggs. What is running rich versus poor?

Thanks for educating me and answering my questions.

Mr. Bob

Well first off, white smoke plus loss of coolant is a bad sign... sounds like head gasket.... If the head gasket is blown dont drive the vehicle....

As for the smell from the exhaust:

Rich running is when the vehicle is over fueling itself... poor running could be anything....

You were told you have to replace your 02?? By who? Somebody who tested your 02 to determin it was bad? or sombody who thought that rich running means 02? It could very well be an 02, but it could also be many other things too....

You will have to get it running properly again to properly test the 02. It is not designed to have coolant going past it...

tc

I think by "poor" you mean "lean".

Rich means excess fuel.

Lean means excess air (not enough fuel).

The combustion temperature is hotter when running lean, and depending on how lean will damage the engine, so the factory errs on the side of running rich. The 3.0 is tuned PARTICULARLY rich.

It sounds like you indeed have a headgasket problem - does your oil look "milkshaky"? I don't think you would damage the O2 sensor, but they're a little over $100 and money wasted when it doesn't solve the problem. What about your catalytic converter - does it get glowing hot?

MTL_4runner

I'd advise to get that truck looked at immediately. Have then do a compression test because no doubt there is at least a small coolant leak into one of the cylinders. Also refill the coolant and have them test for combustion gasses in the cooling system too. Don't bother replacing any sensors until you have tackled this problem first.

surf4runner

running rich = on the way to the stealership / parts store
running poor = the ride home







or what tc said