Ford Excursion :: Code P0304 Cylinder 4 Misfire - Broken Rocker Mount
6.0 .... Have a code Po3o4 Cyl 4 misfire. I pulled the valve cover to remove the injector and found the right half of the rocker mount and rocker arm laying in the head. What may have happened?
View 5 RepliesToyota - Avalon :: 2000 - Rough Idle - Steady Misfire - Getting Codes P1150 / P0300 / P0302 / P0304 / P0306?
I have a 2000 Toyota Avalon XLS with 134k miles, engine is a v6 (3.0). It has a rough idle and a steady misfire. You can drive it sometimes and it will run perfect and you can drive it sometimes and it will misfire. I am getting codes P1150, P0300,P0302, P0304,P0306. Driving me nuts.
View 1 RepliesFord - Escape :: 2001 - Misfire On Cylinder 4 / P0304 Code
I know I can fix this problem, but my question is which cylinder is #4? I don't see it marked on the engine. The counter guys at both my local parts supply stores (whose initials are A and O) can't even look it up for me. If #4 is on the front of the engine, then it's an easy fix. If it's on the backside, then the intake manifold has to come off to get to the plugs and coil packs. It's a bit more labor. I can do it, but I'd rather not have to.
View 1 RepliesFord/Mustang :: 1997 - Getting Error Code P0304 / Cylinder 4 Misfire
1997 Ford Mustang 4.6L EFI engine with 67K miles. The engine is actually now in a Factory Five Roadster. It sat on a stand for 5 years but runs well now with the exception of the code. I keep getting a code P0304 (cylinder 4 misfire) and I've checked the plug - the code seems accurate; it is misfiring.
Things I've tried:
1)swapped plugs,
2)this is a dual coil engine so I've swapped coils,
3)the #4 plug is the longest sparkplug wire so I've gotten high-performance wires,
4)heavily grounded the AL head,
5)put dielectric grease on the plug,
Still, ONLY cylinder 4 gives the misfire.
Intrepid :: 2001 SE - Misfire In Cylinder 4 (Code P0304)
Have '01 SE. yesterday I got a misfire in cylinder 4 (code P0304) the service light blinked on and off 3 to 4 times than stayed solid. changed plugs and boots about 1 to 2 months ago, didn't change coils and they r not in the best shape but didn't have money to replace at time. So I replaced the coil for #4 and it still runs rough with code, plug has some ware but looks fine.
View 1 RepliesS-10 :: 98 Chevy ODB Error Code P0304 / Cylinder 4 Misfire
I left my chevy s-10 truck sitting over the christmas (23/24/25) and it was really cold outside and when i got back i started getting a P0304 (Cylinder 4 Misfire). I replaced the spark plugs and spark plug wires. May be the cold would cause this to happen? I think I've noticed the trucks fuels efficiency drop over the past month). May be the fuel injector(s)? Is the s-10 TBI or does it have fuel injectors for each cylinder?
View 8 RepliesGolf IV / Jetta IV :: Code P0304 On Mk4 2.0 AEG - Misfire On Cylinder 4
2000 Jetta GL 2.0 AEG. I am receiving the P0304 which I have identified as Cylinder misfire #4. I read on some previous posts that I cannot be the distributor because if it was I would be receiving misfires on two cylinders. The spark plugs are OEM NGK and have been replaced recently.
View 2 RepliesPrius (2010-12) :: Code P0304 Misfire On Cylinder 4
Well, I have a big problem on prius 3, the problem is that it has a big and I mean a big body shake when I decelerate above 30 mph or slowly accelerate above 30 to 50-70 mph, when I fully accelerate, the body shake disappears. When the body shake occurs MIL comes blinking and DTC P0304 comes but not always, but the shake is only when the coolant is hot.
On the other hand, if the MIL is not on with the tester it can be seen that the cylinder 4 has misfire margin, only cylinder 4, every time. Now what I have done is to exchange the injectors, problem remains on cyl4.
-replaced the coils, problem remains on cyl4,
-clean the EGR, problem remains on cyl4,
-opened the engine to see the valves, cylinders, pistons, exchanged the ring set,problem remains on cyl 4,
Replaced the wheels, the problem is still there, now I want to replace the drive shafts.
Ford Ranger / B-Series :: 2002 - Cylinder 2 Misfire Code / Idle Rough When Warms Up
I bought this from my brother in better than mint condition. Always maintained. Its generating a cyl #2 misfire code.
It starts and runs like new when cold, but when it warms up, it idles rough, and generates the code. after 1500 rpm it smooths right out and runs fine.
He had it to the dealer just before I bought it and they told him needed a new engine.
I am thinking bad injector, since what seems to be happening is, when cold it gets more fuel, or when u rev it gets more fuel, but at an idle and warm, it doesn't seem to be getting enough maybe. And I see from the maintenance records, a couple of other injectors have been replaced as well.
I think the dealer got tired of replacing injectors under warranty and tried to milk him for a new engine.
2002 ranger extended cab 2wd, 3 door, 232,000 kms 5 speed 3 liter V6, new glass and clutch..
Silverado :: 2003 - Intermittent CEL Code P0304 / Misfire On Cylinder 4
My 2003 Silverado 5.3 has an intermittent CEL. I plugged in the reader and found code P0304, misfire #4 cylinder. I changed the coil, swapped the spark plug and wire from #2 cylinder to see if the code would follow. Nope, didn't follow. I swapped the injector also, same results. My daughter decided to borrow the truck and drove it so low on fuel that the low fuel light came on in the drive way. I added about 4 gallons of fuel and now the light went off. I started the engine after a jump start, and the engine really runs rough and now won't stay running. I am thinking that the fuel filter is probably needing changed because of how low the fuel.
I haven't checked the fuel pressure yet and will do that today. Now, what really puzzles me is the intermittent part. Sometimes it will run with no problem, but then the CEL will come on and the fun begins. The Chevrolet dealer says it's caused by the valves turning in the head and when it reaches a certain spot, it detects the misfiring #4 cylinder resulting in the CEL. If I pull in the driveway with the engine missing, go back out in a short time, start the engine and it runs fine. Same thing if it's running fine and I can start it and the CEL blinks and it begins missing, but may stop and run fine. I am stumped and not so sure about the turning valves.
Grand Prix :: 1997 - Code P0304 - Misfire Only On Cylinder 4 Frequently
1997 Grand Prix 3.8 N/A 181,000 ... I have been getting a misfire only on cylinder 4 which has become more frequent. It "only" happens after the car has warmed up and I turn it off for a few minutes, for instance going in to pay for gas. When I start, it immediately starts to miss but as soon as I hit the accelerator it evens out and runs great, every time. I replaced plugs and wires two years ago with stock.
Upper and lower intake manifold gaskets were replaced around 110,000. All three coil packs have been replaced with original GM packs. I replaced my EGR valve last year due to the original was sticking. My throttle body was cleaned about four years ago. I've seafoamed through brake booster and the rest in gas tank.
I'm stumped that it corrects itself right away by giving it gas. The SES light always come on but goes off on it's own after a few cycles.
Chrysler - Ptcruiser :: P0304 Error Code - Cylinder Number Four Misfire
2006 PT Cruiser Touring Ed. The engine light came on 2 days ago, had it looked at today and the error code p0304 "cylinder number four misfire" was diagnosed. What causes that and what would need to be done to fix that problem?
View 9 RepliesNissan - Sentra :: Check Engine Light Came On With P0304 Cylinder 4 Misfire Code
(This is a continuation of a previous thread: [URL] ..... )
I have a 2005 Nissan Sentra with 75,000 miles on it. Several months ago (see above link) the check engine light came on with a P0304 cylinder 4 misfire code. The only symptom appears to be a rough idle/shaking every 3rd or 4th start for the first 10-15 seconds, but runs smoothly afterwards. My mechanic replaced all my spark plugs (I had new plugs put it at 50,000 miles for the same issue) of which the one from cylinder 4 was worn down much more than the rest. The problem persisted so they replaced my fuel pump and fuel filter and switched the spark coils from cylinder 4 to a different cylinder, but the code still read cylinder 4 so it wasn't the coil. That was back in October.
I took my car back in last week for the same problem and without starting my car (because the problem is worst on the first start) they pushed my car into the bay and did a smoke test, no leaks in the fuel lines. Then they checked the cylinder and said that there was "excess" fuel in the cylinder and replaced the fuel injector. Then after ~3 days the check engine came back on with the same P0304 misfire code. Previous repairs/diagnostics rule out spark plugs, coils, fuel pressure, and injectors.
Ford Ranger / B-Series :: 2000 - Running Rough And Code For Misfire On Cylinder 3 / 2nd Coil Pack
2000 4.2....Last year I had to replace the coil pack when it started running rough and had a code for a misfire on cylinder 3. It is doing the exact same thing now, same code, same cylinder. Is there something wrong that is causing this?
View 5 RepliesAccent LC (2000-05) :: Cylinder Misfire / Rough Idle Then 2001 GS Dies
I've recently purchased an 01 accent GS and I've replaced the timing belt, water pump, and spark plugs. Ive also got no cold air, and original struts with 119k on the vehicle. Those are the least of my worries now as my car loves quitting out at idle; and it does not get any better hot or cold. One of the plugs was completely black when it was taken out (not by me: mechanic work) so that's when they mentioned a cylinder misfire. they wanted an additional 100 to figure out what that could be attributed to on top of the 550 for the work mentioned above! I am now next to broke and want to see if I can trouble shoot some of the causes myself. I am thinking Plug wires, crankshaft/camshaft position sensors (if there are 2 dif ones?) MAF sensor, o2 sensor, injectors, and fuel filter. My understanding is that the coil pack controls 2 cylinders at a time and I just have 1 bad cylinder...I need to figure out where to start as I have no codes to work off of. also, I don't know how to assess resistance with an ohm meter.
View 12 RepliesGrand AM :: 2000 GT 3.4 Keeps Throwing Code P304 - Cylinder 4 Misfire At Idle
2000 Grand Am GT with 3.4 and 150,000 miles. Car keeps throwing code P304 - cylinder 4 misfire. The main issue is the light and needing to pass emissions test. It has just recently had new plugs, wires, and injector #4.
The fuel pressure regulator was replaced about 3 years ago because it was leaking fuel, enough to smell while driving the car with windows rolled down. Shortly after the fpr was replaced, the acceleration problem seems to have started, either by coincidence, or improper installation. The light/error has been occurring for quite some time, about the past year or two. About a year ago, the car was also throwing a random misfire code. I am not positive if both codes were being thrown at the same time, and when exactly the P304 started.
The crank (or cam) sensor was replaced and worked with the issue for a short while (removed codes/light for maybe a few months?) Before the sensor was replaced, the car would stumble at very slow speeds, 0-10 mph. Also replaced Idle Air Control valve last year. The car would sometimes surge on semi warm starts (not cold, not 190-200) between 500-1000 rpms. The surge would be worse when I had the blower running or the rear defrost on, down to 200 rpms at times.
Currently, the car runs perfectly fine for me, except when trying to accelerate on highway ramps. Its firing somewhat when you step on the pedal, but lags and takes longer than normal to accelerate up to speed for merging with traffic. Drove the car after new injection and said it runs fine while driving, but the misfire seems to be mostly or only occurring at idle.
Yaris/Scion & Vitz :: 2003 Echo Throwing A Cylinder Misfire Code / Idle Rough
My friend has a 2003 Toyota Echo that is throwing a cylinder misfire code. Original code is P0302 and P0302PD. The car is idling rougher, kind of sounds like "put-put-put". Also, the car has no power at all. He lives on a hill and he can't even pull out of his driveway. Lastly, the smell of the exhaust is gassy.
We have changed out the spark plugs...no change. Next, we bought a new ignition coil for the number two cylinder...no change. So, maybe its the wiring. Put the new coil onto the number 3 cylinder and the number 3 coil onto the 2 cylinder. Low and behold, the misfire code changes to P0303 and P0303PD.
Thinking we might have gotten a dud of a coil, we bought another. Same thing...new coil on 2 code is P0302...new coil on 3, code is P0303. Could we just have gotten two bad coils? Oh, coils were a BWD brand coil and Duralast brand. Should we just go OEM from dealer? OR Denso from Advance Auto?
Ford F-150 (2004-2008) :: Rough Idle Cylinder 3 Misfire
2004 Ford F150 5.4 Triton 3V Vin5.....
How this started, Drove through a lot of water as our City was in a flood on my way home and and the truck started running rough and got worse over time, I can now barely get to 40 mph as it starts to ping and sputter with no power.. the truck has been parked and not driven while in the shape it's in.
The truck keeps giving me error code P0303 Cylinder 3 misfire detected, P0174 System too lean (Bank 2) and at times another error P0300 saying multiple cylinder misfires detected.
After clearing the codes, I got new codes stating Misfire on Cylinder 2, 3, 4, 6. System too rich (Bank 1) System too lean (Bank 2)
Cleared the codes again and I'm back to Cylinder 3 misfire and System too lean (Bank 2)
What I have done so far... All repairs with in a few days...
1. Changed all spark plugs.
2. Changed all Coil Packs.
3. Changed number 3 fuel Injector.
4. Changed the Oil and Filter. (no water in the oil)
5. Changed the MAP Sensor.
6. Changed Bank 2 O2 Sensor 1 and 2.
7. Loosen the Catalytic Converter on the drivers side to re-leave back pressure thinking the Cat was plugged, still loss of power. I also drilled a small hole in the exhaust at my lowest point to see if it had water in it and it does not.
Checked for vacuum leaks using starting fluid around the intake manifold, no change in idle.. I also checked to make sure the vacuum line was still connected on the back of the intake manifold, I have found nothing leaking.
I also had cleaned the throttle body and changed the throttle position sensor.
Repairs within the last 6 months or less...
8. Replace passenger side cat.
9. Replaced both Bank 1 OS Sensors
9. Replaced Timing chains, Gears, Guides, Guide Tensioners, Oil Pump and pickup tube, Water Pump.
Cam Phasers are fine.
And number 3 coil is getting spark I changed the Ignition Coil again thinking maybe another bad pack.
Still #3 misfire and System too lean (Bank 2).
I am at a loss and not sure what to try, except for a compression test on cylinder 3 but I honestly don't think it's compression or a burnt valve.
Ford F-150 - 1997-2003 :: CEL Codes P0304 / P0456 / P0171 - Misfire On Cylinder 4
So, my 2003 F150 4.6 that I just put back on the road after a four month break is running like crap. I took it off the road for the winter because it was missing (no codes) and didn't feel like dealing with it then but after running it for a day the CEL comes on. It shows the following:
P0304 - hoping it is a coil pack
P0456 - pending. Gas cap?
P0171 - pending. One bank too lean?
Does the 171 code possibly have to do with the misfire in Cylinder 4? I know it is impossible to tell yet but am hoping there is a potential connection.
Before I parked it in January, it was running a bit rough and stumbled on acceleration but never would show a code. Now all this. Going to change the coil first, tighten the gas cap, check for leaks and see what happens but is there anything common on these trucks that I should also be looking at?