09-19-10, 07:45 PM
Hey guys! i got a 99 eldorado etc that all of a sudden out of no where developed a serious misfire and loss of power. it also feels like theres some surging as well. the only code that comes up is a po300. however there is also a u1000 and i belive it was a u1599 or something like that. car has new plugs, wires pcv valve gas filter and fuel pressure regulator. there is no specific cylinder thats misfiring as far as i know. i also checked the plenum for vacuum leaks and came up with nothing. i think the ecm is on its way out but thats just my guess due to the U codes. what do you guys think?