Ok so, I have had this problem for about 4-6 Months and seem that is getting worse. So here it goes. I have a 2004 ford ranger edge 3.0L, its my baby ! and my check engine light is on! I have scanned it about 4 months ago and had Lean codes( P0171, P0174) bank 1 and Bank 2 lean codes, but i also had some pinging so i put some high octane stuff in and seafoamed it was good for a month and threw the engine light on and i left it on.On my way up to my farm in Peterbrough i stomped on the gas and my check engine light started flashing and pulled over and checked the code P0302( Missfire on cylinder 2,) Now i have started to diagnose this problem, i just want some ideas that some people have. I have done a compression test about 5 months ago and found that my compression was a little high avg around 170-180 psi and i have also does a vacuum test know here is where i am a little odd about i was around 19"Hg And it was AROUND, the needle was juming up and down MAYBE 1/2 to 1 "HG, So i am thinking the the intake gasket is leaking. Some people say it could be the fuel pump and i havent checked fuel pressure.? and the check engine light has fashed one other time and both times it said cylinder 2 missfire so thats why i doent think its fuel pressure.
Any help would be MUCH appreciated
Andrew

 

Hey, I had a similar problem, it is probably just a bad coil. Here is my trek through my similar problem:

Date: 1/21/2012 – 1/25/2012
Problem: Code P1151 (Heated O2 sensor—Bank 2, sensor 1, indicates lean);
Code P0301 (misfire Cyl. 1)
Possible Causes: P1151 – fuel system clogged
P0301 – bad plug, bad coil pack, fuel injector is clogged, bad wire;
Attempted Solution 1: New plug on cylinder 1 and fuel injector cleaner

Date: 3/4/2012
Problem: Codes P1151, P0301, P0303 (Misfire Cyl. 3)
Possible Causes: P1151 – clogged IAC, clogged MAF, bad O2 sensor
P0303 – bad plug, bad coil pack, fuel injector is clogged, bad wire
Attempted Solution 2: Did 60,000 mile maintenance, cleaned IAC and MAF

Date: 3/4/2012
Problem: Codes P1151, P0301, P0303
Attempted Solution 3: Replaced coil pack
Comment: Fixed

Ignition coil pack: $76.99 + $5.00 = $81.99

 

I had a similar problem. The truck was missing. No codes when i checked, but on occasion the engine light would flash. After changing fuel filter, MAF, and air filter i had the same problem. The engine was still missing. So i ohmed out my spark plug wires and found one bad. Changed them all, same problem. So finally i ohmed out the coil pack and found a coil bad. The coil took out the plug wire.
I'd say check your plug wires and coilpack.

 

Do a compression check on the cylinder with the misfire. You might have a bad valve. I've done plugs, wires, fuel filter, injector flush on my 02 EDGE with the 3.0L Still coming up with a misfire, and rough idle. Did a compression check, and both #4 and #6 cylinders have low compression. My truck has 150K on it. I'm just going to run it until she can't go anymore. Then throw a remain at it.

 

I have same problem. Codes p0302 and p0171with a bad rough idle and only drives a block then dies bc it bogs out. My question if anyone sees this and can answer, I checked pressure in my #2 cyl and it said 150lbs. Is this okay? No bad valve in that cyl? Truck has 231k miles 4cyl engine. I'm still trying to diagnose the problem.

 

You need to check compression in all of the cylinders, and then compare cylinder number 2 with the others. If cylinder number 2 is significantly lower than the others (ex 130 vs 180 for the others), then you have compression issues caused by either bad rings, valve issues, etc.

There are other tests you will need to do to verify whether it's the rings, gasket, or a valve that is causing the pressure loss.