I have a 2006 trailblazer with 194K has ran good for ever but I was getting a #6 miss fire for some time. But never any engine problems. Till about a month ago started to idle rough and stutter at take off. So I replaced the #6 coil pack and that fixed that code but now I am getting P0300 Multiple Misfires and P0128 coolant temp below thermostat regulation temp. I have read 100 or so of these post and nobody actually says what fixed problem. Catalytic Converter, all new coil packs, thermostat, ECT sensor. Anybody solved this problem if so how. I replaced the CPA and that helped it was clogged. Last oil change I had them put in the High mileage and I think it broke up some sludge from the bottom of the pan or something. Change the oil ran fuel cleaner through it?
2006 Trailblazer with 4.2 I6, hesitation and stuttering
- Thread starter Dixondb
- Start date
BlazingTrails
Member
- Apr 27, 2014
- 19,409
Welcome! You are going to need a new thermostat and Ect sensor use only gm parts. Once you replace the thermostat and with the new coil you need to do a pcm reset. After that you will have to see how it does and we can move forward from there. Cheers
Yea I figured on doing the thermostat and ECM both just to make sure even though I don't see any issues on the gage. But I really don't think that is causing the stuttering problem which is my main concern. I have not replace the plugs yet. I took it for a tune up in the 60 k that I have put on it but they said they were fine and did not replace them. So I figure that is my next step, and will inspect the other coil packs for signs of arcing or other issues. This is my first experience with Coil packs so I am not sure do they snap on like a normal boot? I don't' think I ever got the one I replaced to snap so it may be that it is not making full contact?
BlazingTrails
Member
- Apr 27, 2014
- 19,409
They don't snap on, they just have a spring inside the boot that pushes on the top of the plug. It's pretty hard to get it in there without making contact and you would def know if it wasn't firing. You need to do a pcm reset and clean the throttle body at the same time. When I replaced my #2 coil it still kept throwing a p0302 until I did a pcm reset.
KNBlazer
Member
- Feb 8, 2012
- 811
STOP DRIVING YOUR TRUCK!!! But since it's been driven already with a P0306, you might have damaged your CAT already... the stuttering is the random misfire most likely...you need to isolate that misfire and fix it.... the P0128 is important you fix as well.... on the coils, the way I isolate the problematic cylinder, since I don't own a scanner that gives me misfire counts, is I unplug one coil at a time, plugging it back in immediately until the bad cylinder does nothing at idle....once you find that cylinder, replace the coil with a different cylinder coil, and see if the problem follows the coil....Once that is done, get yourself the parts you need, including spark plugs since it sounds like they have never been replaced AcDelco 41-103, if you use a different brand you might end up with other unexplained gremlins...THANKS GM!!