I'm going with an engine swap from a 305 to 355. When I pulled the EGR off, I just didn't want to put the extra clutter back in. Is it possible to remove the EGR valving and install a block-off plate and suffer no ill-effects with a stock ECM?
Stupid question but it's been so long since I tore it down, doesn't the EGR valve directly feed the AIR tubes for the manifolds? I'll be going with shorty headers anyway, so I naturally want to get rid of the AIR tubes anyway.

Feel free to enlighten me and provide me with any additional information necessary.

 

The EGR valve is the only thing the computer checks. Without it, you will get an SES light for a code 32 after a few minutes of driving.

The EGR valve takes exhaust gasses from inside the head and puts them back into the intake manifold. This dilutes the air/fuel mixture during part throttle cruising, which in turn reduces the combustion chamber tempurature. That reduces the chance of harmful detonation, while also reducing the oxides of nitrogen and carbon that cause smog. The EGR valve closes when you mash the gas pedal, so it does not affect your total horsepower.

The AIR tubes get fresh air from the AIR pump, and accomplish a similar thing as the EGR valve. The fresh air goes into the catalytic converter when its cold to help heat it up faster and let it do is job sooner. Once the engine is warm, the air switches to the exhaust manifolds, to complete the combustion process and turn smog-causing carbon monoxide into less harmful carbon dioxide.

Removing any emissions device on a thirdgen that drives on the street in the United States is a violation of Federal emissions laws, regardless of your state or city's local emissions laws. Please be a responsible hot rodder and keep your car's engine clean. Otherwise, the government may force you to do it by writing tougher laws. None of us want that.

 

so my usual first mod of cutting the cats is illegal???? even though i live in a area with no emission laws even for new cars.

 

Correct, emission devices are federally mandated, not just put there to slow people down.
Removing it is illegal. But hey, if we all did legal things, we wouldnt need 638hp ZR1's.

 

When some people remove their EGR, they do not get a code. It's a coin flip.

 

Not all egr's have a temperature sensor on them.
My '87 Tpi does. My '91 Tbi does not. A friends '92 15 pass van w/a 350 Tbi does.
Removing an egr w/sensor will be the most likely to throw the code.

 

Also to note is that from what I understand the EGR valve is not an effective setup. And a professional tune will yield a much cleaner burning engine even without the emissions devices than what our cars can currently do.

Personally my EGR went bad and was replaced brand new by me and it still does not work properly. This is also not an unusual problem either. Many end up replacing them several times before a working one is installed.

 

HI I need a diagram of how to hook up my EGR system on a 1991 350 TPI that in my 1955 chevy , my shop manual doesn't show it. Pease Help!! Mike

 

I am installing a TPI from a 1985 IROC into my 57 convertible. CArs this vintage are not "legally" required to have Emissions controls - and from what I've read from several forums, there is much less HC and CO when properly tuned.

Now, can anyone tell me how to program around that portion in the ECM?

KT Mac