Just a random thought from a ????? (what'* do you call it when you are somewhere between a newbie and a techie?) but don't discount the possibility you bent the tip on your #5 plug when you installed it.

Roy

I plugged up the scan tool and the live data shows no misses on any cylinder. I did notice that the LT fuel trim closed loop is at 16 at idle. When I increase the rpm'* slightly it goes to zero. If I increase the rpm'* gradually and evenly the fuel trim goes up accordingly until it reaches about 9. If I rap the gas the fuel trim shoots up and I am able to reproduce the stumble somewhat. So my understanding is that positive LT trim numbers mean the engine is running lean and the PCM is compensating right? Maybe its time to test the injectors for spray pattern or am I getting ahead of myself? Fuel pump? By the way I am not a mechanic. I just pretend to impress the wife but this stuff is getting deep. LOL

Hey Roy, Ya know that sounds like a possibility. I had just replaced the LIM though and when I first started it up I heard a pinging in addition to the miss so maybe whatever was in the cylinder disintegrated or burned up or maybe it was pinging because of the miss or maybe I did rap it too hard. I have been accused of that more than a few times. I say if you can't take a good whack ya need to toughen up. She just rolls her eyes and walks away.

I feel kinda dumb but I don't want to deny anyone the chance to learn from my mistake so here goes. My #4 spark plug was so clean because when I changed the plugs and wires I removed the heat shield off the boots. When I reinstalled the wires the #4 plug boot didn't go all of the way down into the heat shield so It wasn't making good contact. Every test on the system was positive but under load I was losing the spark. Things were compounded my the bent tip on the #5 spark plug. It caused a much more noticeable miss at idle and light throttle but it all seemed to go away at full throttle. Once I regapped the plug I was back to the missing under load symptom but it was worse since I had pulled the plugs but not noticed that the boot wasn't making firm contact with the plug. Thanks for the input. Especially Danthurs since I have talked about this in some of my other posts. The bright side is that it forced me to check and recheck and I caught a lot of driveability issues. I didn't realize it but I had been neglecting my baby for a while.bd2bd2bd2bd2bd2bd2

Hey glad to hear you found your issue. I'm still chasing mine but this gives me hope

Thanks, If I have anymore ideas I will shoot them your way. My final approach was to start all over and check the basics so I began pushing and pulling on wires an harnesses.