Ananta1369

Good morning everyone. I hope you are all doing well despite all the chaos that is the world today.

I am looking for some advice from you all regarding a purchase that I am considering. The subject is a 93 z28 with factory LT1 that has the EGR and A.I.R deleted by the previous owner. Looking to replace the rotting Pacesetter LT's/cat less y-pipe with Kooks headers/y-pipe. Prior to noticing the exhaust leak, I always had to deal with the 'rotten egg' smell of the exhaust sitting at a red light and lingering on my clothes all day. I am wondering if I should go with the Kooks Hi-flow catted y-pipe and Kooks LT race headers (non-emission one since EGR and AIR have been deleted). Here are my questions:

1. Can you run cats on headers that do not have emissions connected to them? Is there an issue or am I creating an issue in the long run?
2. Is the 'rotten egg' smell because I was running without a cat and would this help alleviate the smell?
3. Or, should I just go with the Kooks race headers and cat less y-pipe and look into tuning (which is a whole other issue, remember it's a 93) as a way to help alleviate the smell?

I know, seems like simple questions but I'm sure the answers will be more complicated and will lead to more questions. However, for me the bottom line is I am going to order the headers and y-pipe as soon as I hear from the group which way I should go.

Thank you all in advance for your assistance.

chevykid

the egg smell comes from the cats working, no cats, no smell, stronger smell when cats newer. if no emissions connected, cats can't regen, if no regen then the cats plug up after time.

Ananta1369

Thank you, chevykid for replying. Would a proper tune help delay the cats to plug up? Or, just bite the bullet and get the emission Kooks headers and Catted y-pipe and source the EGR and AIR plumbing from a donor car and restore emissions.

UPDATE: I spoke with PCMofNC this morning and he confirmed that he could provide a tune that would account for the AIR and EGR delete and still run the cats (but agreed that without emissions the life of the cats would be limited somewhat) but since I haven't ordered the headers I still have a choice. I like the looks of a clean engine compartment; however, I like to have my investment last and not having strong exhaust odors is just as important.

@Injuneer I have read quite a bit of the post here and recognize you as one of the few remaining experts. What would you do if this was your car and you wanted to have a reliable DD?

Injuneer

https://www.yourmechanic.com/article...ke-rotten-eggs

Try buying fuel from a different source.

AIR and EGR do not "regenerate" the cat.

Deleting the AIR system does nothing for performance. The AIR pump is only there to help the cat heat up faster, while reducing emissions of unburned hydrocarbons during the enriched cold start. Then the AIR pump shuts off and doesn't run again until the next cold start.

If you don't have a cat, AIR serves no purpose.

EGR has little to do with performance. It doesn't operate at idle, it doesn't operate at WOT.

Ananta1369

Thank you for the article and thank you for your reply. This is what I needed to know.