EGR required?

[alf4444]

Does any one know if EGR is required on a 78 blazer 4x4 (originally 400 sbc) with a 350. Also it did not have cats are they required.

[PHOENIX]

There should be a sticker under your hood just to the passenger side of the hood latch. If an EGR is shown on that diagram, then you will need one. If it is not shown, then you dont need it. That sticker will also tell you if you had a cat or anything else emissions related.

[alf4444]

there is no sticker

[BigRed]

It also depends on the state you live in. In Texas, '78s are now exempt.

[PHOENIX]

Call your local inspection location and ask them, they should be able to check in one of their manuals. Have your vin number ready, alot search by vin number. If you feel "iffy" at all on their responce call a couple more. I recommend that either way. Try to get their name or employee number if possible. Try to ask for someone "in charge", you are more likely to get an accurate answer. Either way they are not responsible for the information they give you.

[KIILew]

alf4444 --

Since you state that your '78 Blazer never had a catalytic converter (only the California emissioned Blazers did for that year) it also was not originally equipped with the EGR system. That applies for 350's as well as 400's as originally installed in federal and high altitude emission '78 Blazers.

Hope that helps.

Ken

[alf4444]

thank you that is what i was looking for.

[PHOENIX]

ALF4444:
I just want you to note that he said
"Since you state that your '78 Blazer never had a catalytic converter it also was not originally equipped with the EGR system"
I didnt take it as your truck never had cat converter, I took it as your truck does not currently have a cat converter and you dont know if it did. Just make sure that everything is right. Emissions can be a real hassle! good luck.

[KIILew]

Oops, Phoenix, you're right. You read ALF4444's note more thoroughly than I did...

Still, ALF4444, unless your '78 350/400 Blazer was first sold in California, it was not originally equipped with a cat or egr.

Ken

[PHOENIX]

Hey KIILew do you know when they first starting putting the AIR system on these trucks, subs, or blazers?

[KIILew]

Eddie:

To answer your question very generally, the AIR System can be found on Chevy light duty trucks going back to 1967, if my memory serves me right. Its initial usage, however, was restricted to vehicles sold in California.

The specific model usage of the AIR System during the 1973 to 1992 model year is MUCH harder to chart than, say, the usage of egr or catalytic converters during the same time period. Determining variables included engine displacement, transmission choice, axle ratio, selling destination (California, Federal low altitude, Federal high altitude), truck series/GVW, and model (i.e. AIR application sometimes varied depending on whether the truck was a Suburban, Blazer, or Pickup). Furthermore, almost every year the "rules" of AIR application concerning these variables changed.

Anyway, with respect to our trucks, the earliest models to wear air pumps were the 1973 models. Specifically, all C10 and K10 pickups, suburbans, and blazers wore air pumps- -at least according to factory data books -- regardless of how they were optioned, or where in the U.S. they were originally sold. This also applied to C20 and K20 suburbans. Interestingly, however, C20, K20, and C30 pickups did not use the AIR system. There was one exception: 3/4 and 1 ton pickups sold in California with the 292 inline six WERE equipped with AIR. Of course, the above disscussion applies to the '73 model year; 1974 and later years are a whole 'nuther story...

...until someone asks, I'll sign off here!

Ken