ok my sisters car which is an auto 03 mach 1 with just a catback and an intake spacer just randomly started to shake a lot when cruising when you give it some gas. Sometimes even from a dead stop when you give it gas you can feel it shake before it moves. I just replaced the plugs and it didnt help at all. There are no cel codes either. Any ideas, car has 33k miles and was driven like a 90 year old woman owned it lol

 

bump...

 

Is it bogging or breaking up at all?

 

it boggs down then when you give it a little more gas it moves out. Im thinking fuel filter so thats getting changed tomorrow

 

my car used to do this... plugs didn't help either, once i did plug wires all better..no more miss. But33k miles hmm idk could be plug wires i guess... did this happen recently after the catback or intake spacer was installed?

 

car has had mods since 10k miles, her car has cop's

 

I would try cleaning the EGR valve my car was actually doing this just the other day but threw a code so i took it to autozone for the free checkup. Use some carb cleaner to clean it out, after i did this it ran a lot better it was bogging down to a point where you had to go half way or more with the petal. Car is still running rich so taking it to the shop to get a real diagnostic, but try that and see if it helps at all.

 

my car was doing the same exact thing. finally threw a code. misfire in #2. switched the #2 with #1 coil to see if id get mis fire #1. bc if i did then i kno its the coil. but hasnt acted up since i switched them,

 

it ended up being a bad coil, it was number 4, moisture got in it and ruined it. You probably shouldnt switch the coils the firing order is important ive read