2003 NISSAN ALTIMA EXHAUST LEAK POSITIVE FOR CARBON D IN MY BLOOD MANY PROBLEMS WITH ENGINE LIGHT COMING ON WITH THE FIRST YEAR OF OWNING MY CAR IT STARTED WITH INSTRUCTIONS ON HOW TO SCREW A GAS CAP ON TO AFTER YEARS OF ATTEMPTS TRYING TO CONVINCE THEM IT CAUSED DAMAGE TO MY LYMPH NODES IN MY LUNGS WHEN IT WAS TOO LATE AND THEY SAW VISIBLE SIGNS INSIDE MY CAR LIKE BLACK SOOT AND A STRONG SMELL THEY LAUGHED AND SAID HEY LADY YOU HAVE A LEAK THEY REPLACED THE CATALYTIC CONVERTER AND THE O2 SENSOR WITHIN 6-8 MONTHS I STARTED TO HAVE SYMPTOMS AGAIN NAUSEA,HEADACHES, HEAVY LEGS,WHEEZING & INABILITY TO CONCENTRATE. THEN I KNEW ONCE THE SMELL STARTED THE DAMAGE WAS DONE I DID NOT HAVE THE MENTAL STRENGTH TO FIGHT WITH THEM ABOUT IT ANYMORE SO I TRADED IT IN THIS WEEK I KEPT ALL THE REPORTS FROM THE DEALER WHEN I TOOK IT IN BUT OF COURSE THEY DID NOT TYPE IN ALL THAT I HAD CONCERNS ABOUT. *JB