I've been searching and now unsure, but how does removing or bypassing the smog pump affect the EGR?
EGR vs Smog pump
- Thread starter 95COBRA241
- Start date
MLC Stang
Founding Member
It doesn't affect it in any way. The two systems are completely separate.
The "smog pump", actually called the AIR (Air Injection Reactor) pumps fresh air into the exhaust manifolds during the first couple of minutes of operation with a cold engine. The cats do not work until they are up to temperature. Injecting fresh air into them helps reduce emissions until the cats warm up and start working.
The EGR system recirculates burned combustion gases back into the cylinders to be burned again with the incoming A/F mixture. The purpose is to cool the combustion process which helps reduce certain emissions.
The two systems are not related.
The "smog pump", actually called the AIR (Air Injection Reactor) pumps fresh air into the exhaust manifolds during the first couple of minutes of operation with a cold engine. The cats do not work until they are up to temperature. Injecting fresh air into them helps reduce emissions until the cats warm up and start working.
The EGR system recirculates burned combustion gases back into the cylinders to be burned again with the incoming A/F mixture. The purpose is to cool the combustion process which helps reduce certain emissions.
The two systems are not related.
a50sn95
Founding Member
Like he said...
That's good news because I plan on removing the smog pump and related hoses for cosmetic reasons and because I have an o/r pipe. I know you then have to plug the head with a threaded bolt.
I heard/read about ppl wanting to also remove the EGR, but I thought that would make the car idle bad and also ping from those gases not going back into the combustion chamber. And when you remove the EGR you plug the holes at the intake manifold?
I heard/read about ppl wanting to also remove the EGR, but I thought that would make the car idle bad and also ping from those gases not going back into the combustion chamber. And when you remove the EGR you plug the holes at the intake manifold?
CManT1914
New Member
Paul, EGR is inactive at idle and WOT, so technically it shouldn't effect the idle AFAIK. Somebody correct me if I'm wrong.
Like JT said, the only real way to delete the EGR, is to delete it from the PCM as well. Custom chip, PMS, twEECer, they will all do it.
You might get some part throttle pinging due to no EGR, some do, some don't. If you do delete it, be prepared to run higher octane fuel in case you get pinging.
Like JT said, the only real way to delete the EGR, is to delete it from the PCM as well. Custom chip, PMS, twEECer, they will all do it.
You might get some part throttle pinging due to no EGR, some do, some don't. If you do delete it, be prepared to run higher octane fuel in case you get pinging.
mo_dingo
20+ Year Stangneter 
CManT1914 said:
Yup, EGR is shut off at wot and idle and also until the ECT indicates the engine is warm.
But the smog pump continues to run even after the first 2 minute startup to add O2 into the cats so the cats can convert the exhaust's HC and CO into water (h20) and CO2.
Scott
Thanks for the help!
I really just wanted to remove the smog pump and related hoses. I'll leave the egr alone although I've since found out that the egr doesn't have any effect on power. All it does is recirculate exhaust gases to lower combustion temps to keep the production of Nitrogen Oxides low (emissions).
I really just wanted to remove the smog pump and related hoses. I'll leave the egr alone although I've since found out that the egr doesn't have any effect on power. All it does is recirculate exhaust gases to lower combustion temps to keep the production of Nitrogen Oxides low (emissions).
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