what type of tranny fluid is used on the 2004 FX4 I know its suppose to be full syn but I am only seeing the DEXMerc stuff in the stores and I have heard you don't want to use that..also I replaced the plugs with the champs and replaced 2 cop's I am now getting a slight stumble and an intermittent stall at idle mostly when I come up to a stop now then the truck has 170,000 on it so ear could be an issue I am going to take the aircleaner and stuff off and clean everything with intake cleaner..I know about not getting anything on the map so the TB is more then likely cunked up also how do you reset codes is it just as simple as unhooking the battery for 20 minutes or so? I thought when I added fluid before the reseal job I use mercon V valvoline full syn in the red bottle.

 

went in very easy should say came out and went in easy..the rear was so bad I was knocking soot out of it..now then went to the downstream passenger side and it appears that some one tried previously to remove it and stripped it out so has anyone used a cold chisel ob one of these things with any success?

 

I will try to answer a couple of your questions although based upon what you said, you seem to have it under control and I don't think you are doing anything wrong.

On the transmission, I use Motorcraft Mercon V. the Vavoline full syn Mercon V you suggested looks like a good choice and it may be better than the non synthetic Motorcraft.

Spark plugs I use the Motorcraft plugs and I think they are better because many of the replacements have plated threads on them and they do not seem to stay tight in the aluminum Ford heads on your truck. Plugs coming loose and stripped threads on these aluminum heads are a big problem on older Ford engines.

Disconnecting the battery works for reseting codes. Resetting them with the code reader works even better. Having them reset themselves when you fix the problem also works great.

It is good maintenance to clean the mass air flow sensor (MAF) when you change the air filter and clean the housing. They make a cleaner specifically for cleaning the MAF sensor.

When I change plugs, I also spend a little time cleaning the plug socket so the plug seats properly and stays tight. These sockets collect a lot of dirt, oil, and grease and this can get between the plug and the seat and cause you problems (like misfires). I use a round wire brush (like a plumbers brush or 12 ga shotgun brush), rags, and WD-40 to get them real clean. If you get a little WD-40 in the combustion chamber, it burns up when you start it up.

That Oxy sensor sounds like a problem and I would not use a chisel to get it out. Most of the time, the Oxy code will be coming on because you have a problem in the engine and not because the Oxy is bad. The problem is usually a air cleaner, dirty MAF, vacuum leak, or low fuel pressure. Some good maintenance would be as follows


Change your fuel filter (Cost $8.00)

You are already changing the Air Filter and cleaning the MAF

Change the PCV valve and inspect the hose leading to the valve and replace as necessary (PCV valve cost $3.00)

Inspect other vacuum lines and replace as necessary.

Add fuel injector cleaner to the next tank of gas. I recommend Lucas.

All of the above should make your truck run better and it might result in the Oxy sensor from throwing the P174 or 171 code. As such, you won't have to worry about getting that Oxy sensor out and replacing it. You could also check the connections to the Oxy because the sensor might be good but the wiring connections bad especially is someone was working on it with a pipe wrench to damage it.

 

The oxy sensor was not throwing a code other then when I disconnected it and fired the engine(Dumb) I was just changing them all because the vehicle has 174 grand on it and the stock sensors are there. Going to have to really work on this sensor deal at least it is the down stream one. I used the champions in the 5.4. I am taking the TB off today and cleaning it I put a new MAF in because I got it for 29 bucks or close. What the hell..I am changing the fuel filter with the WIX filter. Good point on the PCV. I found the deal on the forum concerning the TB and MAF cleaning and also found the thread on the Relearn process. I'll get that stuff done today. The sensor deal in the rear passenger side is going to bug me all to hell and back.

 

Did the TB cleaning with intake and Throttle body cleaner and after doing so did the re-learn process under the useful links heading..at first it was idling rough but after the process was nearly done it smoothed out took it for the drive as required and the truck idles and runs better then it ever has. Could not believe how dirty the TB was it was just cuncked up badly. Took me longer to clean it then it did to get it off and put it on. Used dielectric grease on all contacts when replaced. Still hoping to get that back o2sensor out somehow.

 

Good job ceasefire49. Glad it worked out well. I'll have to do this to mine when I change plugs