failed emissions-manifold Q's

ported vac. is what controls the egr. ported vac. is only present at cruise or part throttle cruise, so the only thing it will effect is the eng’s internal temp. it will not harm performance. heres the easiest way to think of a egr. its not meant to burn unburned gases it is a valve that allows inert gasses to be brought back into the combustion chamber to take up un needed space . when at a cruise you do not need the power to take off you just need enough of the combustion chamber to keep you moving along at the same speed , so by allowing the egr to open via a valve that is only opened by ported vac. , which is only present at cruise. you create less energy and less heat. i’m not good at explaining things so i hope you understand.
imo if you replace the cat your car will pass this year but the cat will be overworked and next year you will prob have to get another . this is why techs have to send in a card and the old cat when they replace it with a new cat . b/c of too many misdiagnosis’s .

dattegbol- thank you very much for the replies. Still a little confused about the hook up for the egr but I think I’ve got it. Gonna go test after I hook up the egr.

I think the confusion lies here: The A/T intake has three ports coming off of it (all ported vac to my understanding)
1.) two way check valve to the dashpot
2.) intake tube to the engine
3.) intake tube to the starting air valve (a/t only)(HELMS)

I have a manual intake with only two ports. In the helms tube 16 connects to the egr goes to the control box which contains the (EGR) control valve and solenoid. Then tube #10 comes out of the control box and connects to… can’t see where it goes into from the pictures in the helms ( one of the pictures shows the vacuum line going to relatively where the IM is and not the intake. so I’m not sure where to pull the vac off of so …

I am going to take tube #16 (which comes from the egr) and T it into the intake tube that comes off the engine. Hopefully this will make the egr work and fix the problem. I’ll keep you posted.

as long as it is b4 the throttle plate you should be good. you can actually test the egr by hooking up a vac. hose to it and sucking on the other end while its running. if your car stalls you know the egr functions and the passages aren’t clogged. and do you have the control box in your car, you shouldn’t if it was a man. car.

I passed! Thanks for the help dattegbol- Results are:

                 Limit(g/mile)     Result

HC 0.8 0.2035
CO 15.0 2.0168
NOx 2.0 0.3467

I hooked up the egr to the dashppot vacuum line with a t-connector. I also warmed up the new cat before testing driving for 2 hours (35 minutes continuously before test) and 1/4 tank of gas with three bottles of heet.

the car seems to be running more efficiently at cruising speeds (rpms are lower by about 200-300)

Anyways thanks for all the help. Oh yeah, no control box and the egr operates under vaccum. THanks again.

no prob. bud , good job gettin it goin .
you should have seen my face when i relized it wasn’t the o.g. eng. in my car i was furious , then when i was like o.k. its just an egr wtf i’ll hook it up and see what happens so then i retested it but i had a co prob. b4 and it failed again but nox went way way down thats when i found that the 02 wasn’t moving and the car was runnin really rich . i replaced it and did a motovac carbon cleaning service and the car was runnin so good i was prolly better off breathing the tailpipe air then the philly air. thats the good thing about being a tech with your own emissions dyno…