dailydriver

I know that most everyone on here either does without a re-tune when doing the above, or, is getting a re-tune anyway due to long tube (and other beyond bolt on mods; cam, heads, etc.) installation.

But even with just keeping the stock iron manifolds, and stock type catcons, wouldn't an EGR delete necessitate a re-tune due to changing the actual fuel trims/mixture, beyond the ability of the stock/50 state ECM to compensate for said delete??

Just curious about this (for optimization reasons/my own OCD), as I am about to do these deletes on an otherwise stock (lid, and cat-back) LS1.

Thanks in advance,

Dave H.

patSS/00

iTrader: (6)

EGR only comes on under certain conditions, and then the PCM raises the timing while it's on and also depending on rpm and airflow. So you have to figure that with no EGR and a DTC set, the program is smart enough not to try to turn it on and raise timing at all.

AIR is not an issue, it's only on briefly after start-up. Deleting AIR is a bad idea anyway.

idahoz28

iTrader: (2)

No need for a retune. But you will have SES light come on after deleting these. You will need to have someone reprogram it so the light will stay off.

Snake_Skinner

iTrader: (12)

could you explain why, always thought of it as useless. Thx.

dailydriver

I believe he is claiming this for those very few of us who still have STOCK/OEM style downpipe catcons and iron exhaust manifolds ONLY (NOT for almost everyone else on here who has either longtubes and no catcons at all, or longtubes with aftermarket, bullet 'metal matrix' type catcons).

I was always told that the stockers will NOT 'light off' properly without the A.I.R. system working, and therefore you will 'load up', clog and destroy the stock ceramic honeycomb style catcons with out one (think how rich the mixture is in open loop/warm up).

Snake_Skinner

iTrader: (12)

ah makes sense, thank you.