Jr 98 vectra questions

[madsav]

1998 Holden sedan Vectra 2.0ltr auto with about 220,000k`s
ok lets start
1) Found that the tappet cover/Vally cover was pissin out oil all over the motor, Replaced the rubber gasket and still leaks,should i cover it in a silicon seal or ?

2) Looking down at the front of the motor past the headder pipes you see a oil sender or sumthing ,anyways looks to be oil once again pissin out from around the little sencor any advice or how to fix ?

3)Engine light stays on no matter what even after having holden say there is nothing wrong and wipe it from the ECU,

4) Next to the auto Selector in the car there is a button that looks like a snow flak just wonder WTF its for or does? i thought Air-con but there is a Air-con button on the dash so im lost.

5)Every so often When driving the car will stall,No shutter or warning signs just dies,then you have to turn he key afew times to get it to start again

6)And last question,Do these vectras go alright/Sound good with a sports exhaust system

Cheers

[Astranomical]

4 - You might want to have a look at the manual...given that yours is a Vectra and a '98 I'm not sure as to whether it'll be the same, but my 2007 Astra also has a button near the shifter with a snowflake on it, it activates the "Winter program" which is supposed to give you extra grip on slippery surfaces...given the car's origin (Europe) I'm assuming its mostly intended for driving on snow and therefore not so important here, I've used it on my car and haven't noticed much of a difference.