I have a 2001 Grand marquis ls and the check engine light recently came on i hooked it up to the OBD2 andit said P0301 and P0305 Cylinder 1 misfire and Cylinder 5 misfire so can some tell me what i need to change on it? if anyone has had the same problem please let me know what u did to fix it

 

wires/plugs. check the plugs, they may need to be replaced. you may also need to make sure the injectors are working properly. one guy had a damaged wire going to an injector and after he patched that, it worked fine. try just pushing the spark wires down onto the plugs. sometimes (RARELY) they may work themselves free. and if that''s the case, you may need new wires.

 

Hello Dizzle,


It appears that you and I have the same car. A while back I got code P0307. I was able to find the source of the problem by using an automotive stethoscope to listen to each one of the fuel injectors, while car was ideling. I found that the injector for number seven was not clicking like all the rest. On closer inspection I found the wire harness for the injector had been pulled lose (wires broken). It was an easy repair, and the car ran fine after that.


If your injectors are working fine, I would try swaping your plug on coil packs from one cylinder to another. Take the coils from two cylinder that are working, and put onto the two that are missing. If the misfire stays with those two cylinders (and the injectors are working) then the problem maybe the plugs. (Swapping coils is not that hard at all.)


A few weeks ago a friend of mine steam cleaned the 4.6 in his Mustang. He had a similar problem to yours. It appeared that water accumulated in the recessed sparkplug area of heads, and caused a layer of rust to develope around base of spark plug. In this case a new set of plugs, and also cleaning clip springs inside coil boot (springs that clip onto plug) caused the problem to go away.


Hope this helps.