Any ideas on repeating 303 misfire code on stock 01 Cherokee Sport? It has just started doing this, has 166000 miles, It doesn't smoke, use oil or leak any fluids. I've replaced the plugs with Autolite Platinums. Cleared the code with scanner. IN about apprpx 100 miles, the check engine light came back on, used scanner pulled the same 303 misfire code. Took plug out, none were burnt, all still looked new, cleared code with scanner, drove another 100 miles approx and the check engine light with same code again. Anyone have any ideas? 1st Cherokee I have owned. Thank you,

 

http://www.wranglerforum.com/f5/cel-...3-a-60636.html

 

Insulator sleeves and NGK V-Power Spark Plugs and you'll be good to go.
The 00-01s love NGKs

 

Thank you for th info on the insulator sleeve, I'll defiantly try that..Allan

 

Thank you for the info on the insulator sleeves and the plugs, I'll try both

 

"Insulator sleeves"? What are these and what is their purpose?

 

The fix recommended in the TSB in the above link in reply #2......doesn't always work.

00-01 is the most susceptible to "heat soak" and the accompanying cylinder 3 misfire.

Other things to consider if this problem is persistent include louvers into the hood and my favorite fix is to add a simple timer that keeps the e-fan on for a bit when you turn off the key. This lowers engine bay temps quickly and prevents the heat soak symptoms.