I put the edge in my 2005 150, about two weeks ago. Then last sunday my check engine light came on. The edge said it was a random misfire on cylinder 5, and a misfire on startup. Then it did it again today. is this a big or small problem i should worry about.

 

also it runs and starts fine, no problem i can tell

 

The problem here, is that your truck's computer "thinks" there's a problem! And, since it monitors everythng, I'd say, "Pay attention to it". Bill?

- Jack

 

When did the CEL come on?? Was it on startup, were you idleing, mabey romping on it a lil bit?

 

Could just be a bad COP or spark plug. I would put it back to stock for a little while and see what it does. If it happens while stock then it is not anything the EDGE is doing.

 

get that checked out right away. 04s and 05s are bad leaky injectors which can lead to big problems. dont just assume its an ignition problem. get that baby to a dealer asap.

 

Definitely return to stock and see if it happens again. If it does, go directly to the dealer. Do not pass GO. Do not collect $200.

If it doesn't occur when stock, then consider the following:

The most likely cause for a misfire is either a bad coil, bad plug, or a lean condition. Since the Evo can't physically change the first two, you could be getting a lean misfire on 1 cylinder. The fuel maps used in the Evo can be causing a lean condition which triggers the misfire. Also, do you have a CAI on your truck? That can exacerbate a lean condition which can result in a misfire.

The fact that it occurs on 1 cylinder (and I assume it's the same one each time) leads me to believe that might also have a slightly dirty injector on that cylinder. You might try a bottle of Fuel Injector cleaner in your next tank. I recommend Berryman's B12 which is available at most NAPA stores. Sometimes the simplest solutions are the ones that work.

Hope this helps.

Bill

 

The light came on during startup. So thanks for the info I will do the stuff ya'll suggested! I only got 13,000 miles on it so I hope its not a bad injector or a spark plug already!

 

bill, if CAI is a cold air intake, yes I do have one on.