I always thought the EGR recirculates exhaust gas back into the intake - this dilutes the intake charge - so the car wont run at peak.
An EGR valve is one of those emissions compromises that OEMs had to make for clean air compliance- Not performance.
I would not bother on my Camry but on an old performance sports car this mod is on the table, if I can do it with out getting cross with the inspections and completely tanking re-sale.
Its just one more sub system, to leak or fail and add weight, and in this case hurts performance a little.
Does an EGR only operate during cold start?
For me its the same concept as:
Air Pump (pumps air into the exh manifold, increases back pressure, reduces performance, emissions compromise, another heavy complex system to fail)
Crank Case breather - (dilutes intake charge, oil mist lowers octane, especially bad on turbo car, emissions compromise)
Removing these systems when possible has many benefits when combined with a tune can increase power and in some cases lower emissions (dont ask me to prove that, I read it on the internet :-))
I am a VERY green tree hugger guy. But I dont believer that a few old sports cars that are hardly driven make it worth maintaining these obsolete emissions systems that never worked that well to begin with. My county Emissions board agrees - they dont check emissions after 25 years.
Last edited by Erik L; 08-15-2019 at 09:08 AM.