88 T/A 5.7 TPI . I have replaced CTS , checked wireing from sensor to ECM , replaced ECM . I have gone step by step thru trouble shooting protocall and ending up at bad wireing , ECM , or connector , but I have replaced or checked all . Could a bad prom cause this problem ? Car runs and drives OK but smells rich at idle and cooling fan will not come on . Thanks for any help .