My '04 5.3 has been doing the misfire bump occasionally for a couple of months throwing no codes... Today it got worse and the CEL came on...Went to the local parts store and their reader said PO302 Cyl 2 misfire and PO171 System too lean Bank 1.....
Bought the truck 3 years ago with 92000 and was told the PO had a "complete" tune up done at 80000 because he didn't want any problems...Car dealers and lawyers LOL....

So I'm going to attempt the plug and coil change, I don't have time (family health issue) this week....I do have a Lisle tool, the whole idea of this has me rattled...

First question...Can I put this off for a week or so and still drive it ?

2nd... Can I just change #2 plug and coil and pray ?

3rd....What about buying the "sets" of Moto plugs and I'd guess off brand coils from Feebay ? Looks like thousands have been sold that way....

Lastly ... What is and how do I fix "PO171 System too lean Bank 1" ?....

Sorry I don't post much, I did more when I had my '92...Parked it at 512000 when I got this one, now it won't crank, seems to be a distributor problem...

Thanks in advance too all you guys...And yes, I've done a bunch of "Searching" and just need help...

 

I would first just change the boot and spring on the #2 coil. Most of the time they don't go bad. I'd do that before anything. Then do a relearn. Yes you can ignore it for a week but it will harm your catalytic converter. Not to bad though. Don't buy cheap plugs if you're going to change a plug. Onlu Motorcraft plugs in these babies.

 

I had a misfire on my cylinder 8 years ago. Simply changed the plug and coil and was good until it was time to change them all.

Lean code could be related to the misfire. Unknown right now. Fix the one problem and see if the lean code goes away.

EDIT: I'd get it fixed asap. And ebay / amazon are fine for purchasing the plug and / or coil, I do all the time.

 

Thanks, Stephen....I'll try that tomorrow or Friday...I've read enough to know "only Motocraft" on the plugs, but if I do a full redo, the OEM coils are expensive and Moto plugs and non-Moto coils sets seem to be a bit less inexpensive in sets...Any thoughts ?

 

Thanks ND, I saw your post after I reposted...

 

Coils are ok to go with some of the cheaper ones. The only coil I've had go bad so far was a cheap o. I also have a master craft coil in mine that is working fine for the time being.

 

I would just do boot and spring first before buying a coil. That's even cheaper.

 

I'll do that first after I hopefully make it back from the hospital tomorrow... THANKS !!!!

 

Just thinking out loud here, but it seems to me that a spark related misfire would cause cause a rich condition. What about a failing injector?

 

People need to replace boots and springs when they do the plugs.. this would solve a lot of problems down the road.. got to think of it as the old plugs, plug wires .. those were always replaced on a tune-up.