What's odd is the previous owner installed it, I don't know how long it was on before I bought it but I drove it a couple thousand miles before my first misfire. I'll reinstall the original TB tonight and we'll see what happens.

 

after you re install it, pull your battery lug for 30 mins to clear the computer. Then drive around a bit to let the Jeep relearn everything. Your codes might be popping up from old faults as well.

Go by how the jeep behaves not the light on the dash.

 

I haven't had a CEL since they pulled the head and found nothing but it definitely misfires on startup, not every time but it sometimes.

 

Is it just on startup? and it does not throw a code?

 

It is just on startup and the CEL was lit continuously until the dealer pulled the head, now no code but still misfiring. I put the factory throttle body back on last night, kept the cold air intake as I didn't have a filter to fit the stock airbox. Pulled the neg. battery cable. Started up smooth as silk this morning but it always does that after pulling the negative cable. It does seem to not have as much giddy up go as before but I could be imagining it. I have access to another PCM, just have to send it out to get the VIN changed, I'm thinking of doing that as well.

 

The Viper TB does have better throttle response as you have just witnessed but does not ad any horsepower.. Using a Superchips programmer will allow you to adjust your throttle response to be more sensitive with the factory TB.

 

If the mis fire is ONLY at start up, and not while driving it, It could be as simple as a dirty injector. when it's idleing there is not a lot of fuel flow, and less because of dirt causing a stumble, after you start driving its spraying better and not enough to cause a hiccup while under load. Also, my rig as a little stumble at times when starting up. I pass it off as normal. Every motor will have a hiccup.

I think your rig is fine.

 

It is also possible that a sticky lifter is causing a stumble on start up.
Do you run synthetic oil?

 

So I installed the factory TB, the misfire was worse and now the CEL is back on. I'm going to try and get the PCM from my buddy and have it programmed to my vin and try that next.

 

"If the mis fire is ONLY at start up, and not while driving it, It could be as simple as a dirty injector" I've replaced injector #1. "I think your rig is fine." Thanks for that, do me a favor though, go out and pull the spark plug wire off cylinder #1 and drive it around for a couple minutes, don't worry it'll run fine. It is not driveable for the minute or so that it's misfiring.