does anyone know if replacing the factory catalytic converter with a converter from zap will be good enough or should I just stick with the factory one? any thoughts?

 

oh and another question is I am getting the web address to see which one you all would recommend because the dealership is charging me 600 to replace the cat??? So would getting a zap down pipe with the cat attached be just as good?
here is the link please let me know what you think!
ZZPerformance - ZZP Downpipes #ZZ-GPDP

 

ZZP Downpipe and Cat will still throw the P0420 code on you (most likely)

So if you are failing inspection because of this code, you may still have the code.

Do the research on here, it has been discussed a lot

Change your UserCP settings to show all threads, default it only shows a month old so you probably are missing a lot of the older discussions.

 

Thanks Gentleman
I am about buy a 2003 Monte SS on Tuesday I want to add a cold air kit and a U-tube delete from ZZ's
Very interesting post.
Thanks

 

So I'm a DIY-er and my res has a nice rust hole in it, got the replacement from Walker and its nice but my problem is the 2 bolt flanges from cat to res are very very rusted. I havent really gotten elbow deep in it yet. But my main question is what size is the pipe just behind the flange on the cat to res? Is it still 2-1/4 or is it smaller? Because if my bolts snap (as i feel there going to) I was just going to cut the flange off completely from the cat an use adapters to run into the new res flange (not the way to do it but I'm a saturday backyard mechanic) I need to do this so I can pass inspection within the next coming month. So any info would be very helpful guys!

 

Ooooo. I don't know the answer to your Q. All I can suggest is lube lube lube and HEAT is your friend when removing the nuts. Pre-spray with penetrating oil right away and every day until you do do this job. Heat heat heat when you are removing it.

Anyone out there know the pipe size?

 

Yeah I feel this is going to be a pain. But what I actually might do instead that my friend suggested is cut the old res just before (1inch) the two flanges and work from there. Same size piping (2-1/4) and add new res to old flange, it's a piece and process project. I know there's a lot of Do it your selfers on here so maybe while I'm tackling it ill snap a couple pictures for anyone else who might run into this problem their selves and don't wanna take it to a mechanic.

 

Soak the bolts in PB Blaster the night before and again an hour or so prior to doing the job. If they're still being stubborn a little heat may help. Worst scenario they will break or you can use a cut-off wheel to remove them. No need to cut the flange off - just purchase (stainless) replacement bolts.