Hey I had the same prob and my new thats right only 2months old new oxygen
sensor was gone....shot ..busted.....dead....didnt have to pay cuz it was
under warrenty but put out 200bucks havein the mechanic diagnostic the whole
thing... and he fig. it wasnt that cuz it had just been done but ya know ya
can get a bad one...so I'd definitally check into that ...see ya....
Tim G
87syncro