Misfire issue PLEASE HELP
11-12-2018, 04:15 PM
#1
Thread Starter
Join Date: Nov 2018
Location: Illinois
Posts: 7
Misfire issue PLEASE HELP
Okay so I recently bought a 2003 Mustang GT with 142k miles. Took it home and it started to misfire , read the codes and it was misfiring in cylinder 1,2,6, and 8. So first thing i did was go to autozone and i replaces all plugs and coils (with Duramax brand) , started it up and it ran and drove like a new car. Then the misfire started to come back when i put pedal to the floor. No codes popped up but can tell there is still a misfire. Also when I’m around 1000-1500rpms it will hesitate a lot but stop if i give it more throttle. Any ideas what is going on???
11-14-2018, 02:42 PM
#3
Thread Starter
Join Date: Nov 2018
Location: Illinois
Posts: 7
Yes there was coolant in the holes and when i first checked the codes it said something about lean and my MAF sensor, i cleaned the maf and made sure my intake was on tight. Drove 200 miles so far and still no code for anything but still driving like **** and smells very gassy, I’m thinking maybe 02 sensors? The engine is running terrible but when I’m on highway at 70 or faster it runs just fine ?
11-14-2018, 02:50 PM
#4
Thread Starter
Join Date: Nov 2018
Location: Illinois
Posts: 7
Yes there was coolant in the holes and when i first checked the codes it said something about lean and my MAF sensor, i cleaned the maf and made sure my intake was on tight. Drove 200 miles so far and still no code for anything but still driving like **** and smells very gassy, I’m thinking maybe 02 sensors? The engine is running terrible but when I’m on highway at 70 or faster it runs just fine ?
11-15-2018, 10:14 AM
#7
Resident Ford Troll
Join Date: Jul 2006
Location: Delaware
Posts: 6,717
https://www.americanmuscle.com/intake-manifold.html
11-15-2018, 11:14 AM
#8
Thread Starter
Join Date: Nov 2018
Location: Illinois
Posts: 7
you don’t think it’s an o2 sensor? My right tail pipe has a little bit more “smoke” coming out then the left, i live in Chicago so it’s cold lol
11-15-2018, 01:30 PM
#10
4th Gear Member
Join Date: Nov 2009
Location: SoCal
Posts: 1,826
Just get an oem (Ford Racing) replacement + gasket set. You're looking at about $300, a 6 pack and an afternoon. Very easy job, you can Google for any of the R&R procedure info or get a Haynes manual.
Do not buy a Dorman or any other replacement. Don't waste your time with a Bullitt manifold, as mentioned above there are additional things needed in order to make it work, plus there is the issue of cost and weight and heat soak. And definitely don't waste your time with any aftermarket "performance" oriented manifolds. They are great for engines where aftermarket heads, cams and longtubes are present and to a lesser extent f/i, but on a stock engine you will lose power from idle all the way to 5000 rpm.
Do not buy a Dorman or any other replacement. Don't waste your time with a Bullitt manifold, as mentioned above there are additional things needed in order to make it work, plus there is the issue of cost and weight and heat soak. And definitely don't waste your time with any aftermarket "performance" oriented manifolds. They are great for engines where aftermarket heads, cams and longtubes are present and to a lesser extent f/i, but on a stock engine you will lose power from idle all the way to 5000 rpm.