[99Z28Cam]

i was thinking about guttin my cat converters in my 99 z28 what you guys think?

 

[mnm99]

Do you have to get emisions checks where you live? Just buy some High flows and be done with it.

 

[DOUG G]

Won't say I've done it but seen a few knocked out (all were pre-OBDII)

 

[DjD]

You'll loose performance, that LS1 was designed to run with them... Get headers and a Y pipe and leave the cats. Besides we all have to breath the air so keep it emissions legal.

From a performance standpoint you'll forever be trying to tune without much success and will end up replacing the cats if you gut them.

 

[SixtyAte]

As Dennis said, leave them on. You could buy a set of used cats from the bone yard and gut them. I think you will lose power and mileage....

Kev

 

[Joe Harrison]

OBD II will be messed up. Buy new ones, they are not very expensive. If they have failed you have other problems that need to adressed before getting rid of them. Very little performance would be gained by removing them unless you have major computer mods.

Joe

 

[fatblock]

You will throw the pcm into a tail spin.Fuel management will be affected in a negative way and the SES lamp will blare away at you with a p0420.Even with heated post 02 sensors,a cold cat will trigger a dtc.

 

[m21man]

if you delete them, get your pcm reprogrammed for it.

 

[1stgenCR]

Either run a "test pipe" or leave the factory cats on IMO. High flow cats do indeed flow better but they don't work nearly as well nor last as long emissions wise.

And if you do remove the cats make sure you are tuned for it.

 

[dnult]

From the sounds of other posters, I'd guess this is a speed-density EFI system. MAF systems aren't sensative to changes in exhaust flow since the MAF will compensate for the improved volumetric efficiency. However, OBDII systems have a pre cat and post cat O2 sensor in each bank. If the post O2 doesn't see a reduction in CO / NO2 it will throw an error as others have stated.