For decades, I have used Chevron gasoline almost exclusively. Techron, their additive, really did seem to have made a difference in engines I tore down back in the bronze age, and it never gave me a problem.

But recently, I have tried two tanks of Costco premium gas in my AP2. Don't you do it! Check engine light, turned off and reappearing, and it just didn't run like the smooth turbine we know and love.

Today, I added a bottle of Techron and filled the car at Chevron. CEL is OFF, and the car runs better than it has in years. So smooth, so willing!

Learn from my blunder, my friends.

eoj

 

Personally, I've never been that particular about the gas I put in (except Arco)
My AP1 ran for 150k miles perfectly fine on whatever I put in it. Chevron, Shell, Texaco, Fred Meyer, Costco, or local places (Truax/Towne Pump, etc).
The AP2 has been doing fine on a random mix of Chevron and Towne Pump (close to home and cheap)

 

All gasoline has detergent additives in it. It's required to. In the bronze age of was less regulation where regular fuel wasn't required to have additives (not to mention carburetors), yes I would agree that your problem may be caused by cheap fuel in the tank. In the gilded age of EFI and EPA regulations requiring detergents in all fuels... it's very unlikely that using 2 tanks of cheap gas would foul your system to the point throwing a CEL, one bottle of snake oil and a tank of name brand and poof it's gone completely. I don't buy it. My money is on another underlying issue with your vehicle. By any chance, did you pull the code?

 

As noted above your check engine light should be researched and is unlikely to be a fuel issue.

I have gone through a lot of cars and a lot of years with my AP1 getting gas at the most convenient location that takes credit cards. Never had a fuel issue.

Costco gas comes from a local distribution facility as does a large portion of fuel going to many other stations... an additive package is added but it is still primarily the same gas many other stations get. Fuel will vary in different locations, elevations, states, etc. but it is a commodity these days and generally not different from on retailer to the next.

 

Was it possible that the Costco attendant did not tighten down your gas cap all the way? Could have caused the CEL, then you went back and did your additive plus a new tank- cap gets retighten, CEL is gone...? Sounds more probable.

 

I've heard of people having issues with Costco/Fred Meyer/Arco that have different injectors. Interesting insights though, thanks for sharing Joe.

 

As others have said seems like it was a cap problem or some other underlying problem. My buddy ran a fuel tanker and delivered fuel to stations a couple years ago and most of them all get there fuel from the same depots.

 

A few years ago I noticed how my mpg in a different vehicle went down when I was using gas from Costco.

 

Costco is a Top Tier gasoline, so not really buying the whole 'it threw a check engine light'.

 

So is ARCO though