Coil E code with misfire

hi everyone im new to this website hope to find some help with my lincoln ls v6. my car when going around 50-55 mph starts to miss like it had a miss fire only at that speed the code it gives me says something about coil E has a bad circuit i have change the coil the spark plug and still have the same problem.

Welcome to the forum!

Do you have the exact code number? Also, which coil did you replace? Did you check for coil pulse to the coil? What year is your LS?

-Rod

its 2004, at this point i donet have the code but i will get it today . since this problem has been for a while i lost the code but i change coil on cilynder # 5. when idle its ok its just at that speed 50-55mph. about a year a go the dealership changed the computer because when i steped on it the car just shake like crazy and didnt run.

Did you notice if there was any oil on the coil? On the 2004 that wasn't a common issue. I would expect a code of "coil E" to be related to the primary circuit, possibly the signal to the coil. Usually a secondary issue would be "cylinder #5."

-Rod

no the coil didnt have no oil stains. soo your thinking that the PCU is the main problem? thats what i think. do you know how to take it out?

If you can get the exact code, I'll get some time with the FSM to see what the troubleshooting tree suggests. My computer with the FSM installed on it is in our guest room which is occupied by my sister in-law right now, so my research time is limited right now.

-Rod

the code that it gives me is T0455 hope u can help. thanx

Is it a T0455 or a P0455?

-Rod

p0455 is the code.

According to the factory service manual, that generic OBD-II code (same for all manufacturers) means "EVAP Control System Leak Detected (No Purge Flow or Large Leak)." This code does not relate to the coil in any way.

Possible causes are listed as:


After-market EVAP hardware (such as fuel filler cap) non-conforming to required specifications
Disconnected or cracked fuel EVAP canister tube, EVAP canister purge outlet tube or EVAP return tube
EVAP canister purge valve stuck closed
Damaged EVAP canister
Damaged or missing fuel filler cap
Insufficient fuel filler cap installation
Loose fuel vapor hose/tube connections to EVAP system components
Blockages or restrictions in fuel vapor hoses/tubes (items also listed under disconnections or cracks)
Fuel vapor control valve tube assembly or fuel vapor vent valve assembly blocked
Canister vent (CV) solenoid stuck open
Mechanically inoperative fuel tank pressure (FTP) sensor

-Rod

thanx Rod ill take a look at the EVAP system ill let u know if the problem was solved.

hey ROD thanx for the help i just had my friend put the OBDII on my car and the code for the E coil is P0355. hope u can help.

That's more like it, code P0355 is for the primary side of the coil on cylinder #5. The Factory Service Manual lists the following as possible causes for the code:


Open or short in Ignition START/RUN circuit
Open coil driver circuit in harness
Coil driver circuit shorted to ground
Damaged coil
Damaged PCM
Coil driver circuit shorted to PWR

Fortunately, on the V6 coil number 5 is easy to get to. I know you say you changed the coil already, but did you change the correct one? The cylinder numbering is 1-3 on the passenger side, under the upper intake manifold. Cylinder #1 is at the front of the engine, near the belt. Cylinders 4-6 are on the driver's side, and #5 is the middle one on that bank. Is that the one you changed? Since the misfire seems most pronounced at highway speeds, I doubt the PCM is the cause and really doubt that it's a wiring issue. Unless it is more heat-related than speed related. Have you driven the car around enough in town, running the engine at engine speeds similar to what it's turning at highway speeds?

-Rod

yes i changed the middle on in the driver side bank. yes i have driven the car in town enough and it seems that after a while it gets worse. by the way i also change the spark plug since if in not wrong the sparkplug is the ground to the coil. the temperature in the car is normal unless the coolant temp sensor is not working right.

fuel injector!!!