• Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-

HELP MY CAR IS RUNNING TERRIBLY!

  • Thread starter Thread starter thatcarguymatt
  • Start date Start date Jul 7, 2020
T

thatcarguymatt

New Member
Jul 7, 2020
1
0
1
NJ
Jul 7, 2020
#1
  • Jul 7, 2020
  • #1
Hi Everyone,

New to the group. I have an 03 Mustang GT, it has about 118k miles on it. A little while back I was driving the car on the highway and I heard a loud bang followed by crazy missfires. I got the car towed to my mechanic. Spark plug blew out of the head so he Heli Coiled it. along with replacing all the plugs, and coils. I also had the fuel pump done earlier this year.

Recently my car has been running weird. It will pull fine under light throttle most of the time. and if i slowly apply more gas its usually ok. HOWEVER. when the car is under more load, like high gear slower speed, and i try to accelerate, it missfires like crazy and has no power, then it will catch, and fire correctly for a second and pull fine then back to miss. Its just not smooth linear power as it should be.
CODES
P0113
P0102
P0455
P0457

It seems like its running ok. But I want to fix it so its running as it should be, I am still daily driving it at this time about 30 miles a day. MY GAS MILEAGE SUCKS TOO!

Any tips on what it is or how to fix much appreciated
 
M

MattMan02GT

Active Member
Jul 24, 2018
111
8
28
Albany, NY
Jul 11, 2020
#2
  • Jul 11, 2020
  • #2
The last two are EVAP system leak codes. Have you checked your gas cap to ensure it has a tight seal? Or even put a little grease on it to check?

Another big issue with these cars at this age is there fuel filler neck grommet. This seals around the filler neck where it slides into the tank. Has yours ever been replaced? If you smell gas for a while after you fill your tank all the wall up it's a good indicator yours is dry rotted and leaking.
 
You must log in or register to reply here.

Similar threads

I
98 Mustang GT dying
  • ItsMason
  • May 14, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
3
Views
104
1996 - 2004 SN95 Mustang -General/Talk- Jun 25, 2026
lenzgt
L
T
First Car, what should I do for power??
  • tunedV6
  • Apr 13, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
7
Views
232
1996 - 2004 SN95 Mustang -General/Talk- May 4, 2026
580HP*428Cj
5
Problems after exhaust install and 02 harness
  • djj62478
  • Jul 2, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
35
Views
431
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Friday at 1:32 PM
Noobz347
Who the hell puts the wrong spark plugs in a 3.8L?
  • snowstang
  • Mar 25, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
12
Views
423
1996 - 2004 SN95 Mustang -General/Talk- Apr 3, 2026
LILCBRA
A
Check Engine codes jumping around
  • azactor
  • Jan 9, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
1
Views
176
1996 - 2004 SN95 Mustang -General/Talk- Jan 10, 2026
gkomo
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?