Good afternoon all !

I'll be swapping out my cats this weekend for FI HFC's and am currently sh*tting myself with the stories ive read about the top bolt on the header side. The car has 117k (2004) so you know the bolts are gonna be fun. My question is, does anyone know the size of the bolts? I already ordered gaskets for the header and midpipe sides, now i want to get a set of 10 bolts, nuts, and washers to replace all them in the exhaust. Im assuming any bolt that will fit through the gasket will work, but also what length is required? Or if i'm wrong, please let me know!!

Also, one of the 2 screws holding my MAF into the airbox is stripped. I'm going to need to take it out when i switch my airbox with a rev-up (finishing up the full intake/exhaust before I get my car tuned in a month). Does anyone have a good way to do this or know of a reliable stripped screw kit ? I already have and like the craftsman stripped bolt kit, but i wasnt sure if anyone had other kits they liked.

Last question that I just thought of... if i put HFC's on this weekend, (I already have a catback, plenum spacer, and z tube) will i run into any issues driving lean for a month? I'm in PA and the temperature is gonna start dropping soon. Not sure if ill be hurting my engine a ton for only a month, or if i should try to move the tune up to next week.

Thank you!!

 

Those bolts are going to be hell use Kroil or penetrating liquid on them a day before!!!

 

Rev up air box should use the same MAF housing?

Use FSM for bolt sizes...

Running lean shouldn't be an issue outside of the track day. People freak out over this lol.

 

just dont go wide open throttle and you will be fine....im running lean right now and waiting for a tune as well...

 

ok great.

also, unless someone says its gonna be a problem... im gonna spray the botls with pb blaster every night starting tonight. that should give it 4 days to work its magic on the bolts

 

you are a smart man, although my sister has more breaking strength then PB blaster does... Upgrade to liquid wrench or Kroil!

 

Don't have kroil but I sprayed all but the top bolts with pb blaster tonight . I honestly didn't see an easy way to spray the top ones . Gonna spray them again tomorrow night.

Also checked the fsm, couldn't find sizes, only torque specs. Is there a certain section I'm missing ?

 

When i took off my cats i just use WD40 and let it sit for 5 minutes to let it work in. came off like a champ.

 

Also make sure you have at least 3 feet worth of extensions for your ratchet to get the top bolt between the exhaust manifold and cats. If I remember correctly the bolts are 14 mm.

 

I have a guy helping who replaced his a time or two , he has all the required tools so we should be good. I'm just worried cause when I looked at the bolts last night... they just looked like lumps of rust . This is gonna be fun

 

There is an extra bund for the wideband sensor on the cat right by the header . I don't habe a sensor to put yhere ... does anyone know the size or the threads I can use to buy a bolt or cap to put in there

 

You can get an 02 specific bung plug.

 

Great !! So I just need to find out what brand was in there before ?

 

Brand shouldnt matter. 18mm x 1.5 tpi seems pretty standard for O2 sensor threads. You could always throw an old sensor in there too just to plug the hole. I have never looked, but a local auto parts store may even carry pugs. Otherwise a "speed shop" or theres always Jegs or Summit.

 

Wideband are tbe same size as regular ?
And thanks everyone !!