maxinout93

Ok guys I really need some advice here. Really need to get rid of these pre cats. I hav a temp replacement until I can get some headers. 1 new bank 1 pre cat and 1used bank 2 cat. And y pipe. Not trying to start another pre cat thread because there are many. I more than likely will not install the firewall pre cat and just gut it but the screws at the cat and ypipe are rusted I've been to several shops that just waste my time keep my car all day only to tell me they can't do the work ect. Being that im not experienced in exhaust work im stumped as to what tools I can purchase myself to get this job done as that is keeping me from doing the job. I can easily pull the front exhaust manifold with the front cat attached. Its just the rear pre cat bolts that have me puzzled as how to remove them. Then once removed from the ypipe how to install replacements. Ill be most likely working under the car with ramps and I dont have a torch.

maxinout93

This is what the firewall pre cat and ypipebolts look like on my car. What can I use to get these off and how to replace?




Another view.

Child_uv_KoRn

iTrader: (7)

Ask the guy with the new engine swap thread how removed the manifold. He went out of his way to remove them before he pulled the engine.

I would remove IM, heat shield, Y pipe and crossmember. You'll have to cut the bolts on the Y pipe, those things are pretty shot. Get to the nuts anyway that's easiest for you. Remove the whole damn manifold. It's a waste of time to **** with the precat alone. Breaker bar and regular socket wrench set should be enough.
Just soak the studs in good penetrating lube for a couple days, first.

It'll be much easier if you just get headers, cut off the Y and junk it all except the cats you got for replacements (sell em).

You can try soaking and torching the Y nuts and hammer on a socket. Assuming the tops aren't trashed, you can use a big extension or two and hold it from above the motor. It's likely not worth the trouble. Cutting is faster and easier.

maxinout93

Thanks for your response man and like always u make good sense. Headers would solve alot but what can I use to cut the bolts with?

Child_uv_KoRn

iTrader: (7)

Dremel with cutting wheels or jam an angle grinder up there.

Prophecy99

iTrader: (1)

cut and get new bolts, i had a shop remove (and salvage old stock , for sale by the way) and replace w my gutted cats

took em 8-10 hours mainly dealing with old rusted bolts.

the right shop will do it, it will take time regardless

maxinout93

Ok kool going to buy a Dremel with cutting wheel today. But where do u buy the bolts to replace those. The shop I took it to yesterday said they dont have the bolts to replace with because they are threaded into the cat.

Child_uv_KoRn

iTrader: (7)

Forgot to mention that you'll need to deep well sockets.

Prophecy99

iTrader: (1)

your shop stinks, i had a shop remove mine, and replace w my gutted ones, they didn't have any issues with the embedded studs to the precat or what not, it was just very time consuming. 8-10 hours and 800$ later , ugh makes me wonder if headers would have been easier.

Itz Shak

$800...?? I'm dead meat in that case
What about the option of just cutting the old cats out, and welding in a straight pipe. Too craze?

Prophecy99

iTrader: (1)

custom exhaust work.... w the right shop can be under $500, but hard to find a shop to take it head on thats not a dump

and cutting out cats will need O2 simulator for inspection/emission.

maxinout93

Well I finally found a shop to do the job, and they did it well. I did replace the pre cats with new ones and a new y-pipe as the old set up was badly rusted to the point of no return. So $450 later i feel like i have a new engine almost lol. The front pre cat was pretty much still intact at 191K miles, but the rear one on the other hand was causing me problems with rattling around and extreme power loss/ couldnt even pull a hill at 55mph and all types of engine codes/ power cut/fuel cut and could not freely rev past 2500 rpm let alone anything close to 4 or 5K was out of the question. I appreciate everyones help in assisting me with this matter especially child ov corn you are always right on the money!! Now i have all new bolts in place and dont have to worry about rusty exhaust bolts anymore i will post pictures of the old pre cats soon. So if i wanna get some headers. I can now with ease. Again thanks to everyone because ive made numerous posts about exhaust issues/powerloss, P0300 and it was all related to the clogged exhaust pre-cat.

Child_uv_KoRn

iTrader: (7)

Interesting. It's usually the reverse situation with the precats' condition.

maxinout93

yeah man thanks to you i figured the engine was not breathing like it should and i could only go so fast without a massive power cut. So i had to baby the car for weeks.

Prophecy99

iTrader: (1)

yes he is very knowledgeable =)

maxinout93

you are too man lol, apprecitate all the help. Its running like a champ now, no more rattle noises no power loss, and it revs freely. It was so hard to find a shop to do the job as ive been to almost every muffler place here in this city. It runs better than the first day i bought it.

Itz Shak

Glad to hear it worked out maxinout!
Question.. would gutting just one precat increase the time before the other grenades the engine?
(I'll get it out eventually)

sebastian2041

I recently took of my ypipe which were really rusted with a a wire wheel wd40 pb blaster the right kind of socket breaker bar ratchet amd a 13 and 14 mm wrench they came out it took lots of patience since there was a lot of untighten and tighten again took about 2 and half hours to do... Most compicated part wa o2 sensor whichw e torched and iced to untighten it... Btw thanks for all the great info now i might know why my cars has huge power loss. Good things my headers are coming in soon

Child_uv_KoRn

iTrader: (7)

Potentially, but you can't know the condition without seeing them. Just b/c it's not rattling doesn't mean anything. The surface could be disintegrating slowly and it doesn't rattle. On my spec v there was just a spot about the size of a quarter that started breaking down. Not very big, right, how much damage could it have done? Cylinders are trashed. It HEAVILY burns oil.