If u have a tick ( cam phasers ) that could very well be the culprit. I've read that's the case in few threads. I have low mpg too and am going to do the phasers in the next couple of weeks and hopefully that brings my mpg bs l up. I've done plugs and filters and all that and no mpg improvement. We shall see.

 

Who doesn't have the tick now days lol. Are you seeing any other symptoms on top of low mpg?

 

Changed the aftermarket COP to an OEM and disconnected the battery with a relearn process after. Also pulled the air filter and knocked some of the dust out of it. Seems to be running smoother and no more shutter when lifting off the throttle. Time will tell. Went ahead and ordered new boots and springs from rock auto. Will put those on next week most likely.

 

Installed the new spark plug boots and it really seems to have made a difference. On initial test drive the truck seemed to have more get up and go as well as running much quieter. Hopefully this is what it needed. With the new COP it already was getting better MPG but now I think it will do even better. Will report back in a tank or two.
These are the boots I used.

 

I have found that my truck will idle rough when I've been granny'ing it for too many days in a row. Take it to 4500 for a few seconds when you're merging on to the highway or something. When you get to your next red light she will be so quiet you can't tell she's even running.

I dont know why this works but it does.

 

Mine is weird, it gets more noticeable the more i drive it, when its cold is almost imperceptible

 

How's your oil?

 

I bought a set like this, but the brand from Autozone. I thought it was COPS but it was just a boot and a bunch of springs and have no clue on how to install these. Do you have a How-To or advice on how these install?

Edit Found a great video which explains how to change the boot/spring

 

I hesitated to respond before your EDIT - as I figured that shortly after pulling the first COP off you'd have it all figured out how to install boots! LOL


But the VIDEO... now that's another story. I don't want that guy misleading you about some hypothetical fix for P030x codes. It is all darned good info - and certainly if you read ZERO ohms across the primary the COP is crap/trash. But his method doesn't test the secondary or spark efficiency.


I prefer a more live environment (in circuit) COP testing with the corresponding fuel injector unplugged, and tolerate the temporary misfire using this inexpensive device. You can even approximate how many thousand volts the secondary is putting out.

 

I was more interested in the boot/spring procedure. Also for 10 bucks (your link) it seems like it can narrow down COP issues