Misfire at idle? Transmission fluid and brake fluid questions

This is why most of us say to replace all coils and plugs once a problem like this starts.
 
joegr said:
This is why most of us say to replace all coils and plugs once a problem like this starts.
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Yea I definitely would have done that if these Motorcraft coils lasted longer than 8-10 months. No way I was willing to trash potentially good coils after that period. So I bought a few new ones, and am hunting down the failing ones.

I honestly think I just got a bad batch and my experience is rare, I won't be ordering them from RockAuto again.
 
Andrizzle said:
...I honestly think I just got a bad batch and my experience is rare, I won't be ordering them from RockAuto again.
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Rock Auto has been known to ship off-brands and 2nds in brand-name boxes.
 
Never thought of that. I've had motorcraft could put in at different times with the oldest being about 3-4 years old. I've had multiple misfires and I heard misfires can cause coils to go bad which is possible. How are u going to try and locate your coil problem? Thanks for the advice
 
Your last post is difficult to follow, but if you are suggesting misfires make the coils go bad... Really it is the other way around, the ignition coils are failing - which causes no spark - which causes a misfire in the cylinder.

I was able to get it to misfire really badly one morning when it was super cold, which threw a code. So I replaced that one.

Now I can feel a slight misfire from another coil, but it is not bad enough to throw any codes. So I will be switching out coils this weekend with a new one (one by one) until the misfire is no longer felt. It is supposed to be pretty cold here, so I am hoping to be able to find the marginal coil(s).
 
Andrizzle said:
...So I will be switching out coils this weekend with a new one (one by one) until the misfire is no longer felt. It is supposed to be pretty cold here, so I am hoping to be able to find the marginal coil(s).
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This will work great, as long as you have only one remaining marginal coil. You had at least two before. If you still have two or three marginal coils, you may or may not find any of them with this method.
 
This is true. But hopefully I can feel the difference in multiple misfires @ idle. Like before changing out #7, my LS barely ran and was almost stalling when it was cold. Now it runs smoothly, but I can feel a faint stutter @ idle when it is cold.

My hope is I can feel a slight improvement if I switch a new coil into a marginal one's place.
 
That's a great idea and What i meant to write was I had a p0354 and even after changing the plug and coil that code kept coming up for a while and I drove it for a whole (like over a year and a half) I finally changed the rest of the coils so now the misfire code is gone but could that coil have gone "marginally" bad due to the code being in the system because I reused that same coil again and is still in the car. Thanks for the input
 
Any help on the o2 code? The p0420 I'm guessing is cats but the slow response is the one that bugs me. How should I go about diagnosing the problem
 
I don't want to be annoying but I am waiting on new coils from rock auto but I want to diagnose this slow response problem. Any help would be great thanks
 
^Dip the P0420 is hit or miss, rather misleading. It's an insufficient reading outside it's tolerance during a drive cycle. You could just simply clear it for now and see if it returns. If it repeats instantly every time you reset the OBDII date, it may be necessary to have a look at the upstream sensors plus the converters themselves. Running with misfiring coils for good period of time will in fact spoil a converter. You could of course try some of those off the shelf snake oil CAT cleaners or even sea-foam it.

Have a read here for a better understanding: http://www.easterncatalytic.com/education/tech-tips/the-misleading-nature-of-the-po42o-code/


Scotty's perspective on the ever so 420-friendly code.

https://www.youtube.com/watch?v=dQ5_vLibPLQ
 
Thanks for response I read it and understand it but it says to take care of the other codes first and go from there. The p0133 is my problem and want to fix it properly since I have no idea on how to do it I am gonna start by changing the o2 and go from there. I personally don't think that's the problem but I have to start somewhere l.
 
O2 sensors are swappable left to right, but not front to back. Swap them over side to side. If the code stays with the same side you have an issue to work on, if the code follows the sensor the sensor is bad.
 
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