I don't see my post from earlier...forgive me if I double post.

I put in Champion OE plugs. The lady before me was using Bosch +4 Iridium. I will probably upgrade to those once I determine what is causing the misfire. I'm waiting on my new wires to come in so I can put those on and see how it does.

Any suggestions on how to test the coils?

 

Nope.
The coils rarely go bad on a DI.
They can, but not often.
Do the other stuff first.
While you are waiting for the new wires run some B&G threw the gas tank to help clean out any carbon build up.

 

B&G? I put a bottle of STP fuel injector cleaner last time I filled up. I also ran put a pint of seafoam in the oil and ran a pint of sea foam through the vacuum.

What is this B&G you speak of?

 

Just filled it up for the second time today. It got 12.6 mpg which is better than I expected with all the misfires and how poorly it's been running. Also, I started hearing some ticking/tapping after I changed the oil and ran the seafoam through the vacuum.

Any thoughts on what that could be?

 

what type of oil did you use?

 

Used 10w40 oil and a pint of seafoam. I planned to leave it in for a week or so before I change it again... I thought I'd use a quart of Lucas when I change it next time.

 

Ok - so while I was waiting for my new wires to come in, I went out and splurged on a nice OBDII scanner. Is there any way to utilize this to help me better diagnose my misfire problems? Other than the obvious codes that tell me what cyliner is misfiring?

 

yeah. you can utilize it by telling us what codes you are getting. misfires on certain cylinders or one cylinder? random or not? what type of scanner did you get? does it give you live data?

 

http://www.bgprod.com/products/fuelair.html

I have not used it yet but have heard good things about it.

DO NOT use Lucas oil additive. If you need a oil additive then you need a different oil.

http://www.carbibles.com/additives.html

 

Well the codes I'm getting are referenced earlier in the post. It was coolant sensor and random misfires on several cylinders. I reset them and I'll see what comes back.

The scanner does supposedly read live data. I think it's a pretty good one.

I was hearing a new tick and was worried about something tapping. But the more I listen to it, the more I feel like it's probably an exhaust leak. When I ran the seafoam through the vacuum line, smoke billowed out from the leaks and up into my face! :-)

ALSO - the more I drive the truck, the more I feel like it's a fuel issue. When I'm driving along, it starts stuttering/hesitating/missing almost like it's out of fuel. When I let off the throttle for a second then push it back down - it usually clears up. I'm wondering if possibly the fuel pump is having trouble keeping up, or maybe the line is clogged somewhere??

Do you think I could use this scanner to read live data to tell me what's happening to help diagnose the problemo? I've never really worked with one before.