so i want to get some new cats for my b5. ive got the 2.8 so i need 2 of them. i dont want to get OEM parts cause they cost way too much. i would like to get some sort of magnaflow high flow cats, but i do not know which will fit (the actual size demensions of the cats, i dont want to buy some only to find out they are too big to fit under my car). i want to keep the original "Y" pipe for the o2 sensors, but i am not sure if i can just cut the old cats off, and then bolt on the new ones. or would this be something that has to be welded?

any suggestions as to which catalytic converters to buy?

also i know the piping is 2.5", but can someone please verify that i need 2.5" cats.

also where is the cheapest place to buy some o2 sensors?

 

it has to be welded. i think labree had some glass packs. autozone has 02 sensors for 70 a piece but you have to wire them yourself.

 

Doesnt magnaflow have 'direct fit' replacements? I thi nk it still needs to be welded in the back, but bolts in the front.

 

nope, the cats are connect directly on the flex pipe in the front and have basically no piping. if you order the cat from the dealership, it includes a flex pipe welded onto it which is the way it came OEM. i had trouble finding a shop to replace my flex pipes because it was so closed to the cat.

 

so you think my best bet would be to take the whole exhaust off cats, flex pipe and all, then do some precise measuring and cutting of the cats, then weld the new cats to the "Y" joint and their appropriate flex pipe, put all new o2 sensors in, and reinstall the thing?

what kind of catalytic converters do you 2.8 guys have?