May have found a solution, Throttle body and intake manifold 99 5sfe Federal emissions Options

[ST204GT83]

Took my car to a shop for this EGR cel, they did all their tests and checked things out, no luck, can't figure it out, so they took my car to another shop, the tech has been working on cars for forty years and is familiar with toyotas. He thinks at one time, the throttle body and intake manifold were replaced because the plumbing for the vacuum lines isn't right or something like that, I'll have to talk to him again when I get my car. He drilled a hole in the throttle body, in one of the ports, which got the modulator to work, but there's a timing issue for the vacuum/egr, so it still throws the code at certain rpms. So, my request, if you have a Federal emissions 99 GT, can you post some photos of your engine, throttle body(attached and detached) intake manifold, vacuum lines, so I can see what it looks like. I tried Google, but it doesn't have much to offer.

[GripNSipp]

Do you have the factory service manual. There is all kinds of diagrams with notes on the differences. I could take some pictures of them for you if that might help

[ST204GT83]

Do you have the factory service manual. There is all kinds of diagrams with notes on the differences. I could take some pictures of them for you if that might help

There's nothing in the factory manual, at least the one I got.

[GripNSipp]

Sorry I'm not much help mine is cal-spec too I did hear about a guy who put a federal IAC valve on a Cal-spec throttle body who had some problems