ym42

Misfires = running rough... I have that surging too, it is most noticeable at lower speeds in 5th gear, e. g. 45-50-55mph on cruise control.

Simon1

list all the codes you are having.

Stoenr

Dreaded Ford throttle body/position sensor?

God help anyone that ones a 09+ fusion. voted most car likely to fail. aka = Found On Road Dead

ym42

So, the codes I have are P0430 (Catalyst System Efficiency Below Threshold (Bank 2), P0300 ( random misfire ), P0302 ( cyl 2 misfire ), P0308 ( cyl 8 misfire ). Today I hooked up my laptop to run some OBD tests. After I cleared the codes, I noticed that the LTFT ( long term fuel trim ) is at +20% both banks - short is 0%. Is this normal or something that clearing the codes caused? I checked the voltages of o2 sensors, upstream and downstream. At first I thought I can see the problem. At idle speed the downstream sensor on bank 0 follows the upstream much closer than on bank 2, but at ~2000RPM and cat temp readings above 600-620C both downstream sensors read flat and stay that way at idle too as long as the temp does not fall below 600C, then it starts to fluctuate. So does this mean my acts are OK? Why do I get the P0430 code then??? I am so annoyed with these issues... Do not want to take to Ford because I am afraid it will cost me arm and leg being a diagnostic problem...

moosestang

did you figure out your problem? do you have aftermarket COP's? you fuel trims are high because of the misfires. The 02's see all the unburnt oxygen and assume you are running lean, so they add fuel.

ym42

Dropped in Moorcraft plugs, misfires are gone, completely. Not a single one when cold. Champions were a waste of money... I will see if the codes will go away too now...

BigDinTexas

Glad to hear your problems are fixed... I gotta ask though, what did you have the Champions gapped to? When you replaced them, did they look fouled? Could that have been the problem with them all along?

Don

ym42

I experimented with gapping them differently. It did not help. When I was able to ID the plugs that were the worst I gapped them down from .45 to .40 and to .35 but that did not help. They looked about all the same when I took them out. They were not fouled. They looked all very similar, just like OEM plugs after 100k miles... There did not seem to be anything very wrong with them. I will post a picture later...

wildboi013

Glad to hear you have this Fixed! I have sold alot of the champions for for 4.6 (direct replacements) and It seems to have something to do with the heat range the plugs are designed for. Although the Champion problem solver plugs seem to be better with this problem. I always recommend Motorcraft for anything with the modular engines even if they are this engines Achillies heel...

ym42

This is just to confirm that the source for my P0430 code were bad spark plugs. After changing to new Motorcrafts all codes are gone!!!