lwain56

Engine light just came on yesterday and has stayed on. Last visit to dealer the O2 sensors (two) were replaced and they recommended using premium gas other than that purchased at Kroger. Filled up ever since with Shell V-Power and now after two months and the third time in 6 months engine light back on.
Has anyone had this problem?

ksalno

I had a similar problem recently in my Audi S5. Took it in and they put an additive in the tank and ran it to half full. Then they filled it and put more additive in. They told me to only use Top Tier premium, which in my area pretty much means Shell or Chevron. I had been using premium but hadn't been too selective on brand. I haven't had the light since. My wife's A4 started doing the same thing. So we ran it to empty and filled with Shell V-Power premium and now the light has gone off. I wonder if the refiners have been changing their formulas in a way that throws off the emissions systems?

You can read more about Top Tier gas here Top Tier Gas

StevethePilot

It's got to be tough for manufacturers outside of the USA to produce engines and emissions systems that can deal with what basically are lower grade gasolines here. I'm not being facetious, the refinement of both petrol and diesel fuels overseas, at least in western Europe, is much higher than here in the US. Their fuels are higher in octane and detergents, and Shell V-Power in Europe can actually improve mileage and engine life, both in its petrol and diesel version (the petrol being the only flavor here - with the caveat that it's nothing like the stuff "over there").

Anyway, I'd give that "top tier gas" a shot a few times before heading in for service.

lwain56

Thanks guys. I found out today its a catalytic converter that has supposedly been causing the O2 sensors to code. Dealer is replacing the cat converter tomorrow morning, however, its Top Tier and Jectron or techron additvie from here out.