i was thinking a oxygen sensor at first, now im not certian, seems to run o.k., has both a po 430 & po174 codes, lean bank2. looking through the scan readings it was idling at 1,100 rpm (engine was cold) fuel pressure 38psi. also said "mil active 687 miles" i assume thats how long the check engine light has been on. its a regular 3.0 in a 2003 merc sable. i did put a cam sensor in this car about 4 months ago, car was recently in a minor colission, im sure its not related to these codes, but i thought id mention it on the outside possibility it could be.