Removing smog pump and passing emissions?

[ron chickadel]

removing smog pump and related parts will alter the way the engine runs and will not set a check engine light ! dmv only going to put the sniffer in tailpipe. along car has good tune on it and a clean filter she should pass . tag it antique and you never go through dmv ! plus insurance will only about $100.00 a yr and 2500 mile only . you,ll have to send at least 1 picture to ins com with car parked by your garage.. have a great day !! georgetown dmv is the best - ron

 

[LukeZ]

Ok so I just need a straightforward answer:

If I remove the smog pump and pulley and all that stuff, the lines that go to my exhaust manifold and catalytic converter and plug the holes, my charcoal canister and all those lines (I'd put a filter in the return like to the gas tank), and everything else smog related, would my engine run like crap, would my avg HP and TQ be affected, and would my milage be affected? If any of the answers to those 3 questions are negative and my engine would run worse, how do I fix it? Just get a plain Jane 4bbl carb that isn't computer controlled? Is it that simple? If it's not, then what else would be required?

 

[jiho]

There is no straightforward answer to this. 😀

In addition to the pre-computer carb, you'd also need a pre-computer distributor.

And removing all that stuff is overrated -- UNLESS you plan performance mods as well. And then when you're done you'll have a hard time passing the tailpipe test, especially if you've hopped it up enough to make it all worthwhile!

No matter what you do to the motor, the same tailpipe standards will apply to your car as apply now the way it came from the factory. And your car is held to higher standards than pre-computer cars. The whole reason for computers in the first place was to control what reaches the catalytic converter, so the converter can clean it up better. That's what the tailpipe test is testing.

Sorry, that's about as straightforward as I can make it.

 

[jiho]

Bottom line, a G-body is a trip down the rabbit hole for anyone who has smog testing and is not satisfied with the motor that came from the factory.

Straightforward enough for yas? 😀

 

[Canon_Mutant]

Sadly, removing the smog stuff doesn't do squat toward making your car fast. Neither will putting on headers if that is what you are trying to clear room for? Without MAJOR changes it sadly kinda is what it is. I researched until my eyelids ached before I gave up on doing anything with my 307 and just started from scratch with a big block.

 

[jiho]

I just got back from Delaware DMV, and here's what I saw:

Vehicle Year Type of Inspection
1967 & Older passenger vehicles No Emissions test performed
1968 – 1980 vehicles Idle Test
1981 – 1995 Two-Speed Test
1996 – To current five model year On-Board Diagnostic (OBDII)
Current five model years Exempt

Idle Emission Test – The DMV technician places the probe into the tailpipe to begin test. This test takes approximately 1 minute to complete.

Two-Speed Test - The DMV technician will place the RPM sensor on the vehicle’s hood prior to beginning phase one of the test. Phase two the DMV technician will request that you increase the engine speed to 2,500 rpm. DMV shall not test emissions at a higher engine speed. To guide you through this process, the DMV technician shall direct you to follow the guidelines on the computer monitor located outside the driver’s door. The monitor shows your engine speed and indicates when you are in the acceptable range. This test takes approximately 2.5 minutes to complete.

Now this is smog check! If only California did it this way!

But if you want to mod your motor and get past this, you probably have to hack in some kind of fuel injection setup -- either with custom programming up-front, or that you can program yourself -- and be prepared for fails and re-programming.

 

[LukeZ]

Ok, these answers are getting better... No peformance gain, got it. But, it does clear up some room, which I do want. I think I could still pass emissions so long as I get a brand new cat after removing all that crap, right?

And ok, since removing ALL the emissions stuff would apparently not go over so well because of my computer controlled distributor and carb, what can I remove that will have no effect in the way the car runs and that will just clear up room (smog related)?

 

[ron chickadel]

fir off all i agree with no net gain in power but lots of room for painting and detailing ! on my 85 elcamino and now my 86 firebird both 305,s .you don,t need to replace the cat unless you want .just cap it with i think it 3/3 galvanise pipe cap. as long as you leave egr in there. you will ot affect the ecm.at least on carb cars,not sure on fuel injection. just save all your parts. i should say both my cars are tagged antique .also they only used the probe both times,! co,s were good but hydrcarbons were high but passed. exhaust manifold pipe take a 1/4 inch pipe plug and i believe pipe coming from the cat was 3/4 inch cap.i live in millsboro and your welcome to check it out if your in the area ! just wanted to help don,t mean to step on anytoes , ron

 

[Clone TIE Pilot]

Just removing the emission system will not increase performance and can decrease it. There really isn't such a thing as a performance cat converter, just a waste of money. 10 years ago there were many emission legal performance parts available for g bodies. Such offerings are discontinued and forgotten as manufacturers turn to making performance parts for newer, more popular cars as that is where the profits are now.


However, there are some things you can do, free flowing exhaust like converting to a SS exhaust, used set of emission legal headers, cam upgrade, roller timing chain, dual snorkel air cleaner, recalibrate the carb to L69 specs, and either a L69 or ZZ4 prom chip. Reset the trans to SS specs, and a good rear axle ratio, posi will icing on the cake.