Check Engine Light

I have a 99' Malibu. The Check Engine Light has come on maybe 10 times in the last 170,000 miles. The last two times were closer together. Had the wife take it and and they put a code reader on it. It was at a garage and they though maybe it was a fuel problem and bring it back next week and they would get into it. $50.00 later she went on to work. I told her to get gas and the light then went away.

My question is. How much water in the gas before you have problems.

The stations in my area have some sort of box they can push a button on and it gives them the water content. The place I get gas is always at 1%.
This is an independent station with fuel supplied by a local dist.

The place my wife uses runs 2% and getting them to push the button was complicated it being a C-Store and most of the employees didn't know they could check the water content. Finally I caught the manager in and he checked and told me 3% was OK. This is a company station and they don't know where the fuel comes from

Sorry for the length of this but can anyone tell me have % of water is acceptable

Last question someone told the wfe that the light is set to come on every 10,000 or so miles to remind you to have the engine serviced. Any truth to this.

Thank's in advance. Sam

Water in gas what do you mean. A Malibu thats Desiel ?

No I mean the moisture content of the gasolene you buy at whereever you get gas. I don't know where it comes from maybe condensentation from running their underground tanks to low. Maybe a tanker runnng down the road half empty collecting condensation.

If you know anyone that owns or works where they sell gas ask them f they have a set of gauges thats tells them how much gas is left in their tanks. If they say yes then aske them if they have a test button to push for moisture content......