I have a 2003 Tribute 3.0L and I pulled up codes P0300, P0304, P0305, P0306, P0316. Something has caused the whole bank with 4,5,and 6 cylinders to misfire. I was wondering if anyone has ever had this happen and what could be causing it? Maybe some kind of sensor that controls that whole bank of the engine or fuel problem or vacuum. Any help will be greatly appreciated. Thanks in advance!!!

 

My first guess would be the coil pack and bad wires. If the voltage jumps across coils or wires you will have random miss fires.

 

It dosnt have a coil pack! It is a COP with a coil for every plug and I have new plugs and boots on it. I am led to believe that it is fuel related. I took a screwdriver to the shrader valve on the fuel rail and it didnt have very much pressure at all. It didnt shoot out of there like it should. So I either have a badly clogged fuel filter, bad fuel pump, or bad pressure regulator. I dont know what it is yet. I will be back out there in the morning working on it again. Thanks for the reply..

 

If anyone is interested I found that the cat on the front bank has done blown its guts and destroyed the downstream O2 sensor with no catalyst codes. I now have a gutted cat on the front bank and then found that the cat in the very back was clogged so I have cut it off and straight piped it cause it didnt have any sensors on it. It will now run but still runs very rough. I took it down the road and it ran nice and smooth when I left and went to the store, got back in it headed home and it started stumbling and didnt want to run unless I almost held it WOT. I am at my wits end with this car. Any ideas would be greatly appreciated. I have replaced all the plugs and boots and the crankshaft position sensor and the busted up O2 sensor. If anyone knows anything about these cars could you please help!!!

 

Will: I don't have the same car as you, so I apply my experiences and book knowledge to yours.
You say you replaced the boots on the plugs. Are those the actual coils? Was there oil on the exterior of the plugs and boots? If so the vavle cover gasket is bad and causing miss fires and early demise of the COPs.
The cat failure was most likely caused by excessive heat and or vibration. So you must ask why the exhaust should be hotter than the cat can take. A lean mixture burns extra hot. The EGR system is designed to limit combustion temperature to reduce NOx emission.
Low fuel pressure will lead to lean mixture and higher exhaust temperatures.
A dirty MAF sensor will not cool down enough and make the computer believe there is less air coming in and calculate less fuel for injection.
The guts of the front cat ended up in the muffler and cause excessive back pressure. The pressures between bank 1 and bank 2 are uneven because the straight pipe has less volume than the empty cat.

You can test or have a mechanic test everything for you before you shell out money for parts. You can look for Youtube videos on "how to..."

If the vehicle is still in good shape in terms of body and interior I would check for compression, head gasket leaks and cooling system leaks. And if everything checks out o.k I would replace the complete exhaust system including cats. I would bring the fuel system back in shape. And finally I would make sure that the intake side is clean and seal.
I believe that your situation will require some money to fix. Hopefully you can find good used parts to keep the cost in check.
One more thing: did you have any symptoms before this situation came about?

 

First off thank you for the info...
Now to the info part..
I did replace the plugs and plug boots but not the actual coils. There was no oil or water on the plugs or boots. I replaced the upper intake seals when I removed the intake to change the back plugs. I have not done anything to the EGR system on the vehicle(probably should but havnt yet). I havnt cleaned the MAF sensor. I heard that they make a cleaner exactly for the MAF sensor. I will pick some up and clean it. If im understanding right it will not run smooth with the straight pipe in place of the very back cat. The fuel pressure at the rail was 67psi both when the key was in the on position to power the pump and while turning over and running. There were no symptoms before this came about..

When I got home from work today I started it up and let it come up to operating temperature(no miss or shake or stumbling at all). I drove it around in the field for a little while and it ran fine and didnt stumble at all. It was idling so smooth that it wasnt even shaking the antenna. It was idling at around 700 or 750 rpm in park. I dont know if it just dont want to run at hwy speeds or what. The vehicle is in very nice condition inside and out and has 142,000 miles on it.

 

You need to ask yourself where the guts of the cat ended up. My guess is that they ended up in the muffler and clogged the passages partially. There are enough openings when you idle the car but when you run 3000 rpm there is not enough open area to move the gases out. It builds up back pressure. I get belly aches just thinking about it!
You can verify that by disconnecting the exhaust and drive at highway speeds (you pay the ticket!) or have the back pressure measured. They drill a hole in the pipe and insert a probe to take a reading. Then they plug the hole up with a rivet or something.
A vacuum gauge could also give some clues. But you need experience interpreting the readings. The Haynes Manuals give some hints.
All the other things I said in the previous post are valid but should have no such dramatic effect. I think your coils are good or you would have rough idle. I don't know off hand what the correct fuel pressure is.
I am thinking it would be worth fixing this car right, including a cat. The CEL will likely stay on as long as you don't have a cat. The O2 sensors monitor the cat's performance and yours is nil.
Replacing the muffler (if it is clogged as I suspect) will restore the highway performance to 95% or so. The rest would depend on proper fuel trim which requires the cat and working o2 sensors.
Does that make sense? Usually I am not far off.

 

MAF Cleaner: http://www.amazon.com/CRC-05110-Mass.../dp/B000J19XSA .
Throttle Body Cleaner: Amazon.com: CRC 05078 Throttle Body and Air-Intake Cleaner - 12 Wt Oz.: Automotive

GOOD LUCK!

 

Yes sir that makes perfect sense all except when the front cat blew its guts the back cat caught it and that is why I removed it just to get it back running. I have just removed the rear cat cause it was clogged from the front cat. I have had the battery unplugged and was wondering if it was running rough because the computer had to relearn everything. I know that I have to replace all the cats and stuff and I plan on doing that ASAP, but right now I am just trying to get it running so my wife will have a way of going somewhere in case of emergency. I reved it up to over 4K rpm last night and it reved good and the idle settled down back at 700 rpms and idled smooth. The field behind my house is pretty smooth and I ran it fast enough to make it change gears. It is raining cats and dogs today so I didnt get to do anything to it and dont want to take it down the road incase I have to walk back and get my truck and tow it home. I really appreciate all the help and good info from yall.

 

Will: I see I made slight misinterpretation. Since the second cat acted like a strainer the muffler may not be plugged. If you did not throw away the back cat you may be able to clean it out. I saw a "ScottyKilmer Youtube" on that.
I' be driving this vehicle a while just to see how reliable it is. I don't know how well it is relearning the ropes without valid data from the O2 sensors. It seems to have learned something already.

Good luck