Cylinder 3 misfire. P0303

AFHockey1304 · May 7th, 2008, 11:35 AM

hey, i have a 96gt and ive been gettin a misfire code in cyl 3. Replaced coils, plugs, wires, injectors. All the plugs are good, and they all look the same. Also did IAC, and TPS. Cleaned the MAF, i have a TF upper plenum, BBK CAI, PP Throttle body, bbk shorties, TF underdrives, and full exhaust with high flow cats, if all the helps. Thanks

Lefty10 · May 7th, 2008, 05:39 PM

You run outta gas? Cuz I got that when I ran outta gas...put a full tank in and I was good to go...I don't know if that's what's up with you but who knows.......doesnt hurt to share.

AFHockey1304 · May 7th, 2008, 06:15 PM

no i kno that i have gas, it only does this sometimes, it comes and goes. Usually doesnt do it as bad when its hot. I heard that it could be a bad ground, and i checked it and those were all fine. I have no clue on what else would make it do this..

tom2000r · May 7th, 2008, 07:10 PM

try disconnecting your battery for 1/2 hour...

AFHockey1304 · May 7th, 2008, 09:13 PM

The battery has been disconnected so many times, so i know thats not the problem...i recently had the motor out and put all new gaskets in...

96GTRagTop · May 7th, 2008, 09:16 PM

blow out ur spark plug holes...... again

AFHockey1304 · May 7th, 2008, 09:20 PM

alright dude...but would that cause it to only misfire sometimes..and wat would blowing the spark plug holes do?

96GTRagTop · May 7th, 2008, 09:23 PM

u could most likey just have something on the wire, in the hole.

when i did my intake manifold swap a peace of tape fell in there, car would fire up fine and after ten minutes throw a code

AFHockey1304 · May 7th, 2008, 09:28 PM

ill try that...i also get a code for IAC over speed error...so i replaced it and erased the codes and it came up again..

AFHockey1304 · May 7th, 2008, 09:29 PM

would it cause a misfire if i didn't gap the spark plugs?

96GTRagTop · May 7th, 2008, 09:30 PM

whats the code?

AFHockey1304 · May 7th, 2008, 09:36 PM

i dont know the code off hand but it was idle air control over speed error...but i didnt gap my plugs before putting them in, i dont kno if that would make that big of a difference...

97GT4.6 · May 8th, 2008, 12:37 AM

uh yea, you better gap those plugs dude

AFHockey1304 · May 8th, 2008, 04:52 PM

today i just replaced my fuel pressure regulator and it still happens...i got it scanned and i got codes p0172 and p0171 which means both banks running too rich..any suggestions....

MustangMatt96GT · May 8th, 2008, 05:20 PM

Gap the plugs.... .054"

Not gapping the plugs can cause detionation and poor running...

AFHockey1304 · May 8th, 2008, 05:23 PM

i did gap them and the problem its still misfiring....

MustangMatt96GT · May 8th, 2008, 05:25 PM

What codes is it pulling?

AFHockey1304 · May 8th, 2008, 05:26 PM

p0171 and p0172

MustangMatt96GT · May 8th, 2008, 05:30 PM

clean your MAF also good idea to change your O2 sensors. the missing could be from the MAF being dirty. But you sure that you gapped the plugs to .054 and that the wire in the boot was touching the actual spark plug?

AFHockey1304 · May 9th, 2008, 05:38 PM

just cleaned my MAF and regapped the plugs...would oxygen sensors cause this...when coming to a stop sometimes the car stalls too...

May 7th, 2008, 11:35 AM	#1
AFHockey1304 Newbie Join Date: May 2008 Posts: 17	Cylinder 3 misfire. P0303 hey, i have a 96gt and ive been gettin a misfire code in cyl 3. Replaced coils, plugs, wires, injectors. All the plugs are good, and they all look the same. Also did IAC, and TPS. Cleaned the MAF, i have a TF upper plenum, BBK CAI, PP Throttle body, bbk shorties, TF underdrives, and full exhaust with high flow cats, if all the helps. Thanks

May 7th, 2008, 09:16 PM	#6
96GTRagTop I Post Entirely Way Too Much 1996 GT VERT PI at <3 .0000000001 Join Date: Mar 2007 Location: I killed a man who tried to sleep with ur cat Zip, I'm hiding in that spot we put that thing 1 time. Posts: 5,159	blow out ur spark plug holes...... again __________________ Maybe it's not just the trolls ruining the site, but the people running around bitching about it sucking so much. Do your part to keep this place clean, and keep ur F'n mouths shut about the people who do. Goose wouldn't have shot at Maverick

May 7th, 2008, 09:23 PM	#8
96GTRagTop I Post Entirely Way Too Much 1996 GT VERT PI at <3 .0000000001 Join Date: Mar 2007 Location: I killed a man who tried to sleep with ur cat Zip, I'm hiding in that spot we put that thing 1 time. Posts: 5,159	u could most likey just have something on the wire, in the hole. when i did my intake manifold swap a peace of tape fell in there, car would fire up fine and after ten minutes throw a code __________________ Maybe it's not just the trolls ruining the site, but the people running around bitching about it sucking so much. Do your part to keep this place clean, and keep ur F'n mouths shut about the people who do. Goose wouldn't have shot at Maverick

May 7th, 2008, 09:30 PM	#11
96GTRagTop I Post Entirely Way Too Much 1996 GT VERT PI at <3 .0000000001 Join Date: Mar 2007 Location: I killed a man who tried to sleep with ur cat Zip, I'm hiding in that spot we put that thing 1 time. Posts: 5,159	whats the code? __________________ Maybe it's not just the trolls ruining the site, but the people running around bitching about it sucking so much. Do your part to keep this place clean, and keep ur F'n mouths shut about the people who do. Goose wouldn't have shot at Maverick

May 8th, 2008, 12:37 AM	#13
97GT4.6 Editor 97 GT Slower than JLaw's 98 GT Join Date: Oct 2007 Location: FTC, Colorado Posts: 818	uh yea, you better gap those plugs dude __________________ 97 Ford Mustang GT \|Spec 1 Clutch\|BBK CAI\|3:73's\|SLP LM1 Resonators\|O/R H Pipe\|Mishimoto Radiator\|Steeda Tri-ax \|Cobra Hood\| Bullitt Rims\|Bought but need to install\|Eibach lowering springs\|

May 7th, 2008, 05:39 PM	#2
Lefty10 Regular Join Date: Jun 2007 Posts: 95	You run outta gas? Cuz I got that when I ran outta gas...put a full tank in and I was good to go...I don't know if that's what's up with you but who knows.......doesnt hurt to share.

May 7th, 2008, 06:15 PM	#3
AFHockey1304 Newbie Join Date: May 2008 Posts: 17	no i kno that i have gas, it only does this sometimes, it comes and goes. Usually doesnt do it as bad when its hot. I heard that it could be a bad ground, and i checked it and those were all fine. I have no clue on what else would make it do this..

May 7th, 2008, 07:10 PM	#4
tom2000r Enthusiast Join Date: Jan 2008 Location: ohio Posts: 713	try disconnecting your battery for 1/2 hour...

May 7th, 2008, 09:13 PM	#5
AFHockey1304 Newbie Join Date: May 2008 Posts: 17	The battery has been disconnected so many times, so i know thats not the problem...i recently had the motor out and put all new gaskets in...

May 7th, 2008, 09:20 PM	#7
AFHockey1304 Newbie Join Date: May 2008 Posts: 17	alright dude...but would that cause it to only misfire sometimes..and wat would blowing the spark plug holes do?

May 7th, 2008, 09:28 PM	#9
AFHockey1304 Newbie Join Date: May 2008 Posts: 17	ill try that...i also get a code for IAC over speed error...so i replaced it and erased the codes and it came up again..

May 7th, 2008, 09:29 PM	#10
AFHockey1304 Newbie Join Date: May 2008 Posts: 17	would it cause a misfire if i didn't gap the spark plugs?

May 7th, 2008, 09:36 PM	#12
AFHockey1304 Newbie Join Date: May 2008 Posts: 17	i dont know the code off hand but it was idle air control over speed error...but i didnt gap my plugs before putting them in, i dont kno if that would make that big of a difference...

May 8th, 2008, 04:52 PM	#14
AFHockey1304 Newbie Join Date: May 2008 Posts: 17	today i just replaced my fuel pressure regulator and it still happens...i got it scanned and i got codes p0172 and p0171 which means both banks running too rich..any suggestions....

May 8th, 2008, 05:20 PM	#15
MustangMatt96GT I Post Entirely Way Too Much 1996 Mustang GT 14.217@98.89 MPH at 5800 FT no spray Join Date: Dec 2006 Location: Lakewood, CO Posts: 6,573	Gap the plugs.... .054" Not gapping the plugs can cause detionation and poor running... __________________ If you are not willing to stand behind our troops, please feel free to go stand in front of them! If "drifting" were really racing, they'd have a track for it"

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May 8th, 2008, 05:23 PM	#16
AFHockey1304 Newbie Join Date: May 2008 Posts: 17	i did gap them and the problem its still misfiring....

May 8th, 2008, 05:25 PM	#17
MustangMatt96GT I Post Entirely Way Too Much 1996 Mustang GT 14.217@98.89 MPH at 5800 FT no spray Join Date: Dec 2006 Location: Lakewood, CO Posts: 6,573	What codes is it pulling? __________________ If you are not willing to stand behind our troops, please feel free to go stand in front of them! If "drifting" were really racing, they'd have a track for it"

May 8th, 2008, 05:26 PM	#18
AFHockey1304 Newbie Join Date: May 2008 Posts: 17	p0171 and p0172

May 8th, 2008, 05:30 PM	#19
MustangMatt96GT I Post Entirely Way Too Much 1996 Mustang GT 14.217@98.89 MPH at 5800 FT no spray Join Date: Dec 2006 Location: Lakewood, CO Posts: 6,573	clean your MAF also good idea to change your O2 sensors. the missing could be from the MAF being dirty. But you sure that you gapped the plugs to .054 and that the wire in the boot was touching the actual spark plug? __________________ If you are not willing to stand behind our troops, please feel free to go stand in front of them! If "drifting" were really racing, they'd have a track for it"

May 9th, 2008, 05:38 PM	#20
AFHockey1304 Newbie Join Date: May 2008 Posts: 17	just cleaned my MAF and regapped the plugs...would oxygen sensors cause this...when coming to a stop sometimes the car stalls too...