Can fuel injector service cause cyl 4 misfire

[Darkkd]

Hello,
I recently had the fuel injector service done on my 98 Explorer while at Wal Mart. Initially, it ran fine, but within a couple of days I started noticing a hesitation when I would accelerate as well as a very rough idle. So I had the CEL code read and was told that Cylinder 4 was misfiring (P0304).
So I have a couple of questions:

I realize that there can be many causes for a misfiring cylinder, but is it possible for the fuel injector cleaning to cause a misfiring cylinder directly?
If so, is it possible for an additional cleaning to clear up the problem?

Also, am I causing additional damage to the vehicle by continuing to drive?

Essentially, I am trying to get as much information as I can so that I can have a decent conversation with a mechanic in case I have to take it in.

FYI- I replaced the plugs and wires within the last 6 months

 

[J_C]

Yes it is possible to "service" (what exactly did they do, ultrasonic or soak or just dump some cleaner in the tank?) injectors and dislodge a particle large enough to block the injector.

Yes you could damage the vehicle, the exhaust and particularly catalytic converter by continuing to drive it. If the injector is just clogged and not damaged then it is possible that additional cleaning could clear it up. I'd still take the spark plug out and eyeball it, just to rule it out because it's such a quick and cheap thing to fix if that's the problem.

Before going to the expense of paying a mechanic to do anything, keep in mind that you can get a remanufactured fuel injector from Advance Auto Parts and DIY for $45 - $10 off coupon code A124 ($10 off $30 or more, not sure when it expires) = $35 (with core exchange), but you might see if complaining to Walmart will get you anywhere, maybe they'll take that one back out and clean it again. Maybe it just needs a new O-ring or two... $2. It would be great if they'd take it out and clean it again for free then put on a couple new o-rings that you supply before reinstalling it.