Change original cat

[skullmanonfire]

I have a magnaFlow cat that i would like to put in. What would be the best way to get the old out?
2000 grand prix gt
I got this to del the u bend.
how to tilt engine forward?

 

[gtpeddie]

you bought a cat to delete your u-bend? :th_scratchhead:

 

[skullmanonfire]

Well no just a + its old so changing it

 

[gtpeddie]

do you have a welder? the best way to get the old one out is take the whole DP out and cut out the old cat with a sawzall, and weld the new one in, you have to make sure everything is measured and fit right so when you go to put the DP back in it will fit. and while the DP is out you can get rid of that u-bend.

 

[Scottydoggs]

did you buy a down pipe with a cat in it? or just a new cat?

just a new cat, you need to weld it in.

if you picked up a whole DP then you should be able to just unbolt the stock one and bolt that one back in. i dont know if you need to rock the engine forward at all to do that. im thinking no.

 

[skullmanonfire]

yes its with the down pipe ive taken a look and the only problem would be is to get the bolts off the head of the DP i looked on the fourms a way to tilt the engine to get some room but i could not find any thing.

 

[gtpeddie]

i didnt need to move the engine when i put my ZZP DP in, but i did it on a lift

 

[skullmanonfire]

PONTIAC Grand Prix 1997 1998 1999 2000 2001 2002 2003 3.8L Catalytic Converter | eBay this is the one i have

 

[skullmanonfire]

is there room from under the car to unscrew the bolts?

 

[gtpeddie]

if you have a jack and some jack stands maybe even a set of ramps

 

[Scottydoggs]

you need a new flange gasket and 2 new bolts for the side that bolts to the res, (as they will break) and take the 2 bolts out of the rear exhaust manifold.


a lot of people here say the best way if you have no air tools to take the 2 bolts out of the exhaust manifold is to drive the car, get it hot, then drive up on car ramps or jack stands and take the bolts out when hot, you'll need a long extension and a breaker bar, maybe even a pipe for more leverage.


if you not careful these two bolts can break, if they do, be prepared to maybe have to drill them out and use bolts and nuts.

 

[skullmanonfire]

yes i have a jack and stands, the bolts are rusted so i think im going to have some room to force to bolts

 

[gtpeddie]

this is what it will look like from under neath i had too use a nut and bolt for my DP

 

[skullmanonfire]

i have air tools the only problem is the room from the top of the engine i have almost non is there more if i lift the go from under?

 

[skullmanonfire]

the side with the resonator i got lose but the other side where it is attached to the engine i cant seem to get to the bolts is there room from under the car to unbolt them?

 

[Scottydoggs]

you have to get them from under the car, long extension and that spiffy air gun you got, take them out little by little, even take them out a turn or 2 and and then turn them back in to help clear the threads up.

 

[skullmanonfire]

ill give that a try
THANK YOU ALL!