I was doing a quick check under the hood yesterday trying to find a vacuum leak and noticed the flexible aluminum pipe running from the airfilter box down to the heat shield, I think thats where it ended, was off. How is that attached? Is it necessary? Would that cause a drop in fuel economy(only getting around 18mpg)? The car has 107,000 miles on it, new plugs in the summer, new air filter, but I still have a code for the secondary air problem, I think the code was P0108. Would this trip that code?

Thanks
Neil

The hot air tube attached to the rear, bottom of the airbox and to the metal preheater that runs under the rear of the engine to the exhaust manifolds. This hot air tube is used to help emissions and would not set a code.

DEWFPO

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1998 S90 071,245 and 1995 964 154,100

Does this thing just push onto the preheater or is there some sort of clamp that holds it on? What would happen if I just removed the tube completely? Would the car run any differently?

It just pushes on. You probably will not notice any difference if you remove it.

DEWFPO
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1998 S90 071,245 and 1995 964 154,100

I don't know where you live but if your in a climate that doesn't get very cold and you don't have emission testing in your state I would consider taking it off rather than putting it back on. It is supposed to help the car heat up quicker and bring the emission equipment up to operating speed quicker. The draw back to this thing is that there is a temp thermistat in the air box that can (and often does) go bad and let the engine draw in nothing but hot air. If this takes place two things can happen,you can fry your mass meter and you can lose one or both of the power stages that are bolted on to the intake for heat sink purposes.
Not telling you to do away with it just giving a breif overveiw of what and how.
If you have a code that relates to the air pump I would bet that the valve that is hooked to it is corroded and needs to be replaced, it has a vacuum line hooked to it that runs across the top of the engine to it.
Hope that helps
Poolman

Thanks Poolman, I live in the Chicago area so it does get cold and I do have to get the emissions checked every three years or so. If I did rempoe this and aloowed my car to reach normal operating temp before the test do you think I would have any problem?
The valve you were explaining, was that the PAIR valve on the passenger side of the engine compartment or is there another one buried down on the driver's side. My air pump does start for that short period of time when its cold outside so I'm assuming that's not the problem. I was always suspecting that valve but haven't replaced it yet.Can that valve be easily checked. I thought I saw a post that said to either suck air through on side or blow in one side to see if its functioning.
Thanks
Neil

Many of us with 200's have taken the Hot Air tube off of their cars.
I have emission checks in NY every year BUT they do not look under the hood to see if it's all assembled, they run the car with the Sensor on the exhaust and if it passes...it passes.
Even on the coldest days, the elimination of that hose doesn't affect the engine.

I can't understand why many States look for the emission equipment to be installed, my thought is "if it runs clean, it should pass.
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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me

It's the valve right next to your air pump-the pump is hooked to it. Don't for get to check that temp part in the air box.
Poolman

Sorry double post.