Heres my situation. I have a 91 TBI with Vortec heads and an lt4 cam. I have the cat and AIR system removed. I have headers with AIR provisions and a NON-EGR manifold.

Emmisions tests have been implemented in my county and my car doesnt stand a chance!

I know i'll have to put the old cam back in along with the smog pump and cats.

I need to know how to retrofit an EGR system. I've seen those tubes that run off of the driver side AIR to the manifold but those seem like they would always be routing exhaust into the intake. Wouldnt the trouble code still set? What else will i need to do. I am SCREWED!

 

get into chip tuning, get a custom prom, remove the EGR codes. then hope and pray you pass the sniffer.

 

i dont really have time to do all that. I want a fool proof way of passing. Im just about ready to convert the car all the way back to stock

 

that sucks man

 

sorry no fool proof fast way to pass a car that is missing emmisions equipment. you might get lucky and the tester will have no idea what a smog pump, or egr valve looks like, and you will pass visual. there are ways to cheat on the sniffer test, but if you fail visual inspection, that does you no good.

 

Sounds like you need to slip the guy at the shop a bribe for a free sticker, other wise you have alot of work ahead of you . Its not worth the work and money your gonna have to put into it to pass just talk to some people its alot easier to get one that way then the mods your gonna have to do to pass emissions

 

I'm thinking about filing a low income waiver. This would be 100% legal, because in all actuallity, I'm a broke college student

 

is this your only car?

 

yes sir ... i may also consider selling it

 

can you register in another county(not country) that does not have emmishions testing and send renewals to a PO Box ???

 

I wish someone would make some, ummmm, 1.35 ratio rockers for emissions testing. That would save some work on cam replacements.

Here is what I did to comply with EPA requirements as far as EGR is concerned. I routed the exhaust from the header AIR tubes into the intake manifold. An EGR valve is still used to regulate the allowance of exhaust gas into the engine. I used the stock EGR chip information and have no error codes using this setup.

Are you sure that your state is checking for NOX?

Another good idea is to learn as much as you can about the testing program http://www.tnrcc.state.tx.us/air/ms/vim.html

I learned that in Illinois, you can take your car in for a voluntary test ($20) that gives actual treadmill results and doesn't count against your record.

S-D

 

if that line runs directly to the manifold then how does the EGR regulate it??????

I wanna put my old cam in just because i think the car will perform better and get better mileage. With the lt4 it fouls the plugs and offers NO lowend. However it does sound pretty rad at idle with my cut out open

 

Exhaust enters the intake at right, flows over to the EGR at left and then, when the EGR is opened, flows up towards the TBI unit.

With all emmsions equipment and appropriate changes to your chip, you could likely pass emmisions, have more power and no SES lights.
The chip is a large part of the solution.

 

also i would use premium fuel and some octane booster and i think az or pb sells stuff to bring your nox down... its like 6 bucks or so but i can't remember the name.

 

oh also depending on the year of the car the tests are sometimes more leaniant for the older cars. also you could buy the 50.00 universal cat from jegs with the air tube coming off it and run it up to the egr... just a thought. it would be easier than the idea of removing the cam. also some states have laws were you get the inspection then if you fail you have x number of days to fix it. which would give you more time to do the chip!
also you could get a fpr from the junk yard drill a hole in the side of it and put a tap in it then run the line to your intake. this will lean it out at idle which is were they test for nox!!! then once your done just put the old one back on or keep it

 

1) He will be tested using the two speed idle (ASM) test. They do this on 95 and older vehicles.

2) This would bring only a small volume of exhaust gas up to the intake. Since he alread has headers with an AIR provision, draw exhaust from one side of the headers and pump AIR INTO the cat and the opposite side header to help complete combustion and keep operating temperature where it should be.

3) Chip work would go a long ways here.

4) Why not just tune the chip as mentioned above?


WHOD1: Here is a link to a 1 page summary of the ASM test. It much easier to pass than the one here in Illinois (Lake County). is : http://www.txdps.state.tx.us/vi/Misc/all_asm.pdf

S-D

 

1. What chip/ECM are you using? Stock?

2. What fuel pressure are you running? Stock?

3. You need to get the car tested first to see where you stand -- so you need to get an emission test done for tuning ONLY, not for inspection purposes. Some people call this a pre-test. You still pay for it, but it doesn't count towards passing or failing.

4. The production LT4 cam has enough overalp built-in so that it provides self-EGR -- which is why the LT4 in the 1996 Corvette had no external EGR valve. Yes, you can add some external plumbing (incl an EGR valve) to make it look ok, but functionally the cam provides the overlap needed to retain some of the combustion products inside the cylinders.

5. the AIR system, at least on L99/LT1/LT4 engines was designed to run for 4 minutes after start up, so that the cats got heated as quickly as possible. That's an electrical air pump, not the belt-driven one used on your 91. Technically, since you are suppoised to test the car after is it nice and warmed up, you would have no need for the AIR system other than that it looks like you have one.


6. You have the L31 heads, so you have the best heads you could have combustion + emissions-wise. They help a lot more than what you had on there before.

7. If you don't have cats, you MIGHT need them... and that depends on the emissions pre-test you get done and item #8 (below). It is possible to have a well tuned LT1-type engine pass an emissions sniff test without cats, but the tuning has to be correct. In your case, you will probably need them because it's not likely you will have tuning that's that precise.

8. ECM tuning. You're whining a lot about how screwed you are, but you have no idea how good/bad things are, and I get the impression you threw parts at the car, it runs well, but you have no idea how it stacks up emissions-wise, nor have you mentioned any attempt at doing any tuning. Tuning, btw, allows both emissions-compliant operation as well as enhanced performance.

That's a lot of words. In short, what you need is tuning. There is no good reason why you can pass an emissions test, but you can't rely exclusively on the LT4 cam, headers, L31 heads, stock tuning + raised fuel pressure (which sounds like what you have at the moment).

And OBTW, 1.35 ratio rockers won't solve your problem. They would reduce the cylinder filling on each stroke so there would be less air ingested in the engine -- but the fuel delivery from the TBI would still be what you have now. So it would only make your problems worse (too rich).

As far as the cam being responsible for fouled plugs and no low end -- sorry, but that's just wrong. The plugs are fouled because your fuel pressure AND injector pulsing are not tuned to the new air delivery of the exhaust/heads/cam. The LT4 cam (production LT4 cam btw, NOT the LT4 HOT cam which is something else) is mild as performance cams go, and the LT4 had 325-340 ftlbs rating at 4000 rpm, and above 300 ftlbs at around 1500 rpm, so when tuned properly, you won't have any low-end torque problem.

The cost to swap back the stock heads/cam etc nevermind the time, is probably going to be a lot more than if you spent money and time into tuning the ECM. You could even drive up to Tulsa and have the car tuned on Ed Wright's dyno, so long as he can also test the emissions at the same time.

HTH.

 

does the lt1 cam have any overlap to allow egr?
if so i can take mine off the manifold then since the one i have is stuck open!!!

 

oh it has #55 injectors, but i still have the stockers laying around here somewhere. I forgot what the FP is at.

Heres why I cant do tuning on this car. I'm a full time student, I'm working almost every second that I'm not in school. I dont have the ~$200 to buy the tuning equipment because i have to pay for: rent, food, insurance, and the ticket i just got for driving with an expired inspection. I have a professional shop that i can work in, so throwing some of these parts back on isnt TOOOOO big of a task. I have all of the old parts laying around the shop (cat, muffler, old manifold with egr, heads, cam, air system)

Even though the cam has that high overlap, it will still make the code 32 come up which will fail me. The manifold i have does not have provisions for egr =(

i think when i get out of work today im putting the car for sale on ebay. Do you think anyone will buy it with no inspection?

 

someone from a diffrent area might buy it!!! my friend has bought 2 from out of state and both would not pass inspection!

 

register in another county? we can do that here in wisconsin! only a few have testing.