Trouble Codes P0300, P0316 on my Sport Trac.

[greenman0013]

Hey, I'm new to these forums and I have an 02 V6 2wd Sport Trac. About a week ago, the check engine light came on. Nothing was out of the ordinary, It wasn't missing and appeared to be running fine. This started after i started it and about 30 min before I did put some gas in it.

I took it down to Autozone, they hooked up the diagnostic reader and it gave a code of P0300 (random missfire). Its got 113k on it so i figured i would just change out the plugs and wires. I also added some fuel treatment, thinking it may have been some bad gasoline. After about 100 miles the light went off. So I'm thinking i fixed whatever the problem was.

Well today (about 300 miles later) I started it again, check engine light came on again. Still doesn't appear to be missfiring, seems to be running normally. Had the code checked again and now its reading P0316 (missfire with in first 1000 Rev).

Anyone have any ideas or suggestions? Could the indicator light be bad? What else can i check? Thanks in advace for any

[way2old]

The P0316 can be caused by different things. Too rich on initial startup, too lean on initial startup. Moisture condensing around an ignition componet can also cause this. It is a really hard code to diagnose as to the various things that can cause it. You need to check all the ignition parts rteally close.

[shorod]

What type of spark plugs did you install? If something other than OEM style, or one of the Bosch platinums, that could be the issue. I've read on here that the V6 can be a bit picky on spark plugs. Seems like a lot of engines, certainly not just Fords, are not good candidates for the Bosch platinums as well. I'm not sure what the reason. I've used the regular Bosch platinums in the past with few complaints, maybe it's more limited to the multi-electrode plugs that have the most issues.

-Rod

[greenman0013]

Originally Posted by shorod

What type of spark plugs did you install? If something other than OEM style, or one of the Bosch platinums, that could be the issue. I've read on here that the V6 can be a bit picky on spark plugs. Seems like a lot of engines, certainly not just Fords, are not good candidates for the Bosch platinums as well. I'm not sure what the reason. I've used the regular Bosch platinums in the past with few complaints, maybe it's more limited to the multi-electrode plugs that have the most issues.

-Rod

They were Autolite Platinums. I have had bad luck w/ Bosch in the past...so I haven't actually tried any of their plugs in awhile. The light actually went off today.

I also changed my air filter while I was at it. Don't know if that could have caused anyting. It wasn't in new condition, but it didn't look bad either. The only thing i noticed there, was that the rubber gasket around the air filter had been compressed a good bit. So the case that it sits in was not seated tightly and I did notice that if I pressed on the air filter housing my engine seemed to run smoother. It was running smooth before but there was a very minor noise it was making..it was hard to describe, kinda like a sucking sound, that was fixed when i changed the air filter out. Guess it had a leak or something.

[shorod]

You may want to make sure that the air intake tubing between the air filter housing and the throttle body is secure and installed properly. If there is any unmetered air entering the engine, you can get a misfire like what you'd expect from a vacuum leak. You may also want to consider cleaning the Mass Air Flow (MAF) sensor. There are special cleaners on the market now specifically for this.

-Rod