• đź’ˇ Fun fact. Whenever you start a thread, TCG Mechanic 5000 (our AI bot) will reply to you to start helping. It doesn't know everything and it will struggle with more complex questions but it can get the thread going and provide valuable information. You can choose to disable it prior to submitting a thread.

P0304 Misfire in Cylinder 4

Blownbyyou

TCG Elite Member
TCG Premium
Mar 27, 2008
3,878
3,975
So last night I was driving home and unfortunately my 2011 SHO decided to crap the bed. I was wondering if anyone has had this issue before...

On the expressway i gave it a little gas (not past half throttle) and saw check engine light start blinking, then notice a definite miss fire. I pulled over and ran the code and got the above code.

I had it towed to an independent shop and they think its an injector and I am thinking I agree because i noticed last night that the afr on one bank was 14.xx and the other bank was 9.xx.

They don't really seem to want to do the job, was wondering if anyone has done it or if its another issue?


P.s. the car has a unleashed tune on it with a 3 bar map (running fine before that).
 

Gone_2022

TCG Elite Member
Sep 4, 2013
13,094
7,525
Looks like the injector replacement is just over 4 hours, and looking at the procedure a decent amount has to come off to do it. Alone with quite a few warnings and bolded items saying if things are not routed in a certain way or removed a certain way further damage may occur.

They may not want to chance it idk
 

Chet Donnelly

TCG Elite Member
TCG Premium
Aug 19, 2004
18,368
38,807
Had the exact problem last week on my 2012 MKS (Unleashed tune + 3 bar). I flashed back to stock figuring if it happens again I'll just take it in for warranty, but the issue hasn't repeated. Mine happened about a mile from my house so I limped it home.

Torque app pull below...

aa95c34b2125ee4e80387c36349dbe0b.jpg
 

bikrboy128

Some say.....
TCG Premium
Jul 15, 2007
12,878
11,502
Wheaton
pull coil 4 and swap with another cylinder, clear codes and drive. fords are common for ignition coil failures, i know ecoboost engines can chew up spark plugs too. maybe check cylinder 4 plug while you're in there.

these days, injectors very rarely fail. cylinder 4 on the SHO is the front bank (radiator side) first coil on the passenger side. super easy to get at/swap.
 

blakbearddelite

I'm not one of your 'shit-hole' buddies!
TCG Premium
Jun 28, 2007
29,201
9,024
FL
My 2V Mustang went through some coils. I had a really bad misfire and there was nothing wrong with the plugs. We swapped out all eight coils and never had a problem again. Though if I had the time, I would have just preferred to replace the bad ones. But it sounded like a real pain in the ass to swap them one by one and figure out which one(s) were bad.
 

Blownbyyou

TCG Elite Member
TCG Premium
Mar 27, 2008
3,878
3,975
I honestly couldn't tell you if they fix themselves. I replace them just because I've had a couple come in and while your pulling codes, the cylinder will be filling with fuel and you'll see it come out of the exhaust.



Are you at a dealer? I recently read they have a 70k mile warranty /7 year warranty on the injectors....

I honestly think that is my problem because I moved coil and plug from 4 hole to 5 hole and the problem stayed In hole 4
 
Old Thread: Hello . There have been no replies in this thread for 90 days.
Content in this thread may no longer be relevant. Consider starting a new thread to get fresh replies.

Thread Info