So, here's the deal. When the weather outside is cold, (near frost in the mornings) the engine is fine. But when it gets warm on a sunny day then my check engine light will go on and tell me I have a cylinder 4 misfire. Is this weird? Is does it just sound weird to me? Any ideas on how to fix it? I've tried replacing spark plugs etc, but that did not help. Gas cap is fine also...

 

Nothing? Not even a "use the &%$^ search function?"

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Lithel &raquo;</TD></TR><TR><TD CLASS="quote">Nothing? Not even a "use the &%$^ search function?"</TD></TR></TABLE>

Use the search function...feel better?

When this light comes on, does the engine run bad?

Are you sure it's only when it's warm out? Well then don't worry about it til winter.

 

I would say that maybe it has to do with intake air temperature but that's about all I can deduce from the temperature outside being the determining factor.

 

Often, a bad o2 sensor will display these symptoms. Best bet is to get the code.

 

I think he has the code, because he knows its a #4 cylinder misfire.

 

How long has it been since you replaced your fuel filter? Have you checked the cap and rotor? How long has it been since you replaced your plug wires?
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Arsenal &raquo;</TD></TR><TR><TD CLASS="quote">Often, a bad o2 sensor will display these symptoms. Best bet is to get the code.</TD></TR></TABLE> How is a bad o2 going to trip a cylinder misfire?

 

I have checked the fuel cap and actually bought a brand new one.

Spark plug wires were replaced within 8 months ago.

Rotor?? What do you mean?

Fuel filter hasn't been replaced in a while.....could that be it then?

 

Not fuel cap, distributor cap and rotor. The fuel filter is truly a once in a lifetime change, around every 110k miles or so.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hatchling37 &raquo;</TD></TR><TR><TD CLASS="quote">How long has it been since you replaced your fuel filter? Have you checked the cap and rotor? How long has it been since you replaced your plug wires?
How is a bad o2 going to trip a cylinder misfire?
</TD></TR></TABLE>

Read. A bad o2 sensor will cause a cell once the engine has warmed up alittle, hence his symptoms. However, I do agree that it won't cause a mis fire, I never stated that it would.