Computer adjusts fuel trims and different factors like timing advance, so yes.

This is almost exactly what I went through, previous bad running conditions hurt the plugs or something of the ilk. Replace the plugs and you can feel the coilpack that is on its way out, it has trouble making enough spark to ignite the mixture under load (from what I can tell, coilpacks with any significant mileage are all in different states of dying). Under load was the only time the missing would start happening. We had just bought the car when this was going on so the thought was "maybe we are driving it wrong". It was horrible plugs and a coilpack that was nice enough to just go ahead and die so it was obvious which one needed to be replaced.

Now get an UltraGauge on there so you can know when the car throws a pending code that will tell you exactly which coilpack is having trouble... I am not an UG salesman, but I don't know of any other reliable way of knowing exactly when the ECU throws a pending code. Then you can put the car under lots of load and force the code to come.

 

theres a device if you have a touch product from apple and it plugs into your car and gives a wifi signal and it moniters your car i was thinking of getting it still reading up on it to see the pros and cons of it i think it even works with laptops

 

Hi, I am not a regular poster and not much of a car expert, but I recently had this same situation and wanted to post my info in case it helps others.

I have a 2007 Fit Sport and started having the misfiring/hesitation problem around approx 75k miles coming back from a vacation where the car was loaded down. Between 50-60mph it would start hesitating, especially when going uphill, as well as random other times, sometimes even when stopped at a light. One time, when attempting to accelerate quickly on an uphill on ramp, the check engine light flashed briefly, but then it stayed off. I took it to the dealer after that, and they said they could not find a code in the computer, and could not reproduce the issue.

After that, I scoured these forums and decided to have my mechanic replace all the spark plugs and coil packs based on what I read. The mechanic said they were able to hook up some diagnostic equipment, and reproduced the problem and agreed that is what I should do. Now I have been driving it for a week and have not had the hesitation issue at all, so I am pretty confident that this fixed the issue.

 

i like happy endings.