I have done a search and I can't seem to come to a conclusion whether or not the EGR will cause detonation if removed. I am ordering mac mids and have thought about removing the EGR since I won't have any cats to help maintain the backpressure in the exhaust system. I will have the EGR tuned out along with the AIR system so I won't throw a code. Would it be better to keep the EGR system intact even though I may have a backpressure issue because of the deleted cats? I really would like a definite answer to this.

 

Mine has been gone for years, no probs whatsoever, its supposed to lower the combustion chamber temps, but it only does this on light cruising throttle, never on wide open passes. I haven't heard any detonation in my car. It may very from car to car but I haven't seen any problems on LT1s. In my opinion it just soots up the intake manifold.

 

It will be fine so long as you delete the cats

 

Directionally it reduces the chances of detonation. The fact that you don't hear detonation means nothing, since the knock sensor picks it up and the PCM is pulling timing before you can hear it. Pulling timing reduces fuel economy under cruise conditions. But how often do you lug your engine in the wrong gear? I doubt anyone who is performance minded ever does it. And on the rare occasion it does happen, the knock sensor is there to prevent damage.

 

If you zero out the egr timing advance table you wont detonate.

 

Not Cats, No EGR and No AIR in DALLAS??? You do know that Dallas is going to emissions testing just like Houston, and they will smell you coming over a mile away. Just my 2 cents, as you will probably have serious issues getting it inspected every year.

 

Nope. all you need to do is have your pcm tuned to pass. They will hook up the obd2 and boom you pass. I do it all the time in illinois w/ no cats. Obd1 you may be ****ed.

 

There still is visual inspection and here in TX they do the sniffer test and with no CATS and EGR you will never pass that test - LEGALLY.

 

Dave, I don't think they sniff obd2 they just plug into the port. The places that I go to don't seem like they are too interested in looking to see if all of the emissions are in place.

 

Maybe you're right, doesn't make much sense that they sniff OBDI and not II though. Probably better in Dallas but here in Houston they have become ***** on the emissions, even had some guys I knew get their Mustangs impounded and fined 2K by DPS when they were caught racing and the officer did a visual inspection and saw they didn't have cats.

 

Man, now you've got me thinking. Dave, if you don't mind me asking, what are the specs on your stroker? Do you daily drive it?

 

I'm running the typicall 383 with the Eagle kit, SRP pistons (11:1 comp), mild CC305 cam, AFR 190 heads w/afr hydrarev kit, JBA mid headers, PCMforless tune, etc.. I'm putting down about 450-470 hp and 450ish torque at the wheels but can't remember as I had it dyno'd over 8 years ago. Unfortunately, I don't DD her (I'd love to) but she is a weekend queen and only sees about 500 miles a year and still has 48K on the clock. Just a PIA to have to go thru the sniffer every year, but I pass with flying colors as I am still running EGR, Air and Cat and with the 305 cam I burn cleaner than some new cars, however if I went with the 306 I might have problems unless my tune was spot on from what I've heard.

 

FYI - Just thought you'd like to know Rallyboy that I'm passing thru your neck of the woods now as my wife and I are on the road headed to Kansas. Gotta love verizon air cards!!

 

The reason they don't "sniff" OBD-II is because they added all the extra emissions systems checks in OBD-II. That's the whole purpose of OBD-II. In theory, if you don't have codes, your emissions systems are working and its likely that the engine is emissions compliant. Hence, a check of the PCM is adequate. They will probably rethink that when they realize that people are modifying the PCM programming to beat the system. Its common in many states to not tailpipe test OBD-II cars, but to fail them if the SES light is on, or a PCM scan shows codes or excessive "system not ready" flags.