Service Engine Soon and Bad Gas

[dragon672]

I've got a 97 Jimmy that I brought in 2005. Right now it has 129,000 miles on it. Since Sept the Service Engine Soon light has been going on and off and lately for the past 2 months its been staying on more than staying off. I have unplugged the battery cables and actually had to have a new battery installed. The fuel pump was replaced 2 years ago. I took the truck to the garage and they scanned it with the scanner and the verdict was bad gas. I've put in a bottle of the Gas treatment from Vavoline that I was told to put in and switched to 89 gas. I let the gas run down into the red--at least I thought it was the red but it wasn't--stupid floating gas gauge. I then filled it back up to a 1/2 tank and let it run down again and filled back up to about 1/2 tank or so. The light stayed off more than it had before but it would come back on when the gas gauge was between 1/2 and 1/4 tank. Now it has come back on for 2 days and this time I let the gas run into the red before filling back up a 1/2 tank of 89 gas.

What else can I do for the bad gas error? I'm thinking about taking the truck back to the garage tomorrow and letting them scan it again to see if I still have the same problem. When they scanned the truck the guy did 2 different tests to make sure it was the problem. I've gotten gas at the same station and then at another station. IF its the station there sure should be a lot more people with the same problem because this station does a lot of business.

Thanks for your help in advance.

[maxwedge]

What is the code and how does it run, lots of info your post but nothing pertinent.

[dragon672]

I don't know what the code was. When they showed me the screen it said fuel contamination. I don't remember seeing a code.

[maxwedge]

No such code as fuel contamination someone is giving you BS, get it scanned at AZ if possible ,we will need that code to progress here.

[rlith]

I'm with maxwedge on this. No such code, verbal or otherwise. For all we know your idiot mechanic could have read an 02 sensor code..As Max said, swing by Autozone or Advance Auto Parts and have them scan the code. Write the actual number down and repost it here. The do the scans for free 7 days a week.

[dragon672]

Well I took it back yesterday and before I got there the light had went off. But they hooked it back up anyway and the garage is using a MAC tools computer so it comes up with this error P0174 - Fuel Trim System Lean Bank 2 and then either P0170 or P0171 I can't remember which one. Well we lift the hood and the truck is idling funny; which I hadn't noticed before. Turns on the hose leading into when the air filter and everything is that mixes the gas was had came loose. We don't think it was the orginal problem though but that the comtanted fuel was the problem. I know the computer said comtanted fuel on the read out because I saw it with my own eyes. I guess it shows possible fixes for the code or something.