Being kinda cheap by nature I was using Costco gas. Premium in Xfire and regular in 08 Nitro and 97 Wrangler. Within one week we experienced fuel sytem problems on all three cars. Xfire had both oxygen sensors fail and check engine light came on. Nitro also had a warning light come on and dealer said problem with number 5 injector and my Jeep started cranking a long time to start which is always a problem with fuel check valve. I fixed the Jeep by running a tank of shell premium along with a can of Seafoam in the tank which fixed it.

We have quit buying gas at Costco. I am just wondering if anyone else on the Forum has had similar problems with Costco gas.