Misfire on #4 and #8 despite having all COP's and sparkplugs replaced one year ago. Was also showing "...fuel to lean (PO171 & PO174)

Also got a "B1230" for the wheel sensor.

Could this be a vacuum related problem? What are the chances of both #4 & #8 misfiring at the same time after being replaced a year ago?

If is it a vacuum leak, where (Other than PCV valves and tubes) should I check? And what is the best method for doing so? Someone mentioned spraying carb cleaner around and wait until you hear the engine rev but I'm a little leary of doing that.

The "ABS" light has been coming on every once in a while as well.

Any ideas/help/insight would be greatly appreciated.

Thanks in advance.

Tim
97 Expy 5.4V8 Eddie Bauer 4X4

 

my 98 exp xlt 4.6 has been driving good until yesterday, the CEL came on I check the code, P0303 CYL#3. This is getting out of hand I just had the coil pack replace & wires & spark plugs. Its like I have a ghost is in my truck. what eles can it be????

 

Ok I started my truck up today 1998 exp xlt 4.6L, its still misfring. I was driving it down the road so I turned on the AC, guess what the misfring stop. IDK what going on, have anybody ever had the issue with the truck. it misfires but when you turn on the AC it stops..

 

There is an issue with the alternator harness on some vehicles. The harness rubs against a metal pipe, chafes, and can cause misfire codes or even shuts down the engine intermittently.

Start here: https://www.ford-trucks.com/forums/9...ml#post9213727

 

That link is for 03-04 expeditions

 

Yes you can easily dismiss the possibility like you just did, OR, you can check out your truck to see if it could also be the cause of your problem.