2004_mustang_gt

I have a 2004 mustang gt and the car hardly gave any power and rattled at high rpms's and the engine light was on so I took it to midas and read codes p0309 #5 misfire and p0430 cat converters inefeccient. So I changed all my spark plugs and all the injectors and still not much of a difference. The car still acts as if it wasa 4cylinder car having hard time going up hills, etc. I was wondering would changing the cats make a huge difference in power or should I take it to Ford? Thanks

SikGT

Have Ford diagnose it for like 80 bucks or something then tackle the problem yourself depending whats wrong with it. It's probably cheaper to replace the mid pipe than to have the stealership do it.

96GT226410

I think that the cats are under federal warranty. I think they're warrentied for 7 years/70,000 miles.

2004_mustang_gt

I have a rebuilt mustang gt and live in canada, would they still be under warrenty? thanks

videoassault

Pull your coil out and look at your boots. I had cracks in my boots right at the tips where i had to squeeze them to see, but it cause my car to miss. Took it right to my brother in-law and he pulled my boots and yep that was the problem replaced the boot and that fixed my problem try doin that before speening all that money

02 Ninja

Change your Font Size!!! You're killing my eyes trying to read this. LOL!!!! I noticed you said you have a rebuilt stang, did you have it rebuilt or was it rebuilt before you purchased it? If you had it rebuilt, was it running fine before the rebuilt.

2004_mustang_gt

I bought the car rebuilt and was running like this from the start. thanks