Ok lol i'm going to describe as much as i can to get a better diagnosis.
420A turbo portfueler stage v
I had some intercooler work done along with EGR delete done at a shop called big 3 racing. I was boosting 19 psi when i took it in. When i got it back it was hitting 22 wouldn't spike and go down just a steady 22.Since the car is built i thought nothing of it and maybe that they messed with the boost controller when testing it. so i put half 94 and 110 in drove it for a while.Then i started having issues with the trans which i just replaced not to long ago. It started randomly choosing when it would want to go into second. All shift cable where fine. So i try to get it home with 1-3-5 because they were the only gears i had.Then as i'm getting on the highway i only went into to boost just a little bit the car takes off as if in WOT and went to 35psi.So as i'm trying to focus on the cars ahead of me i didn't think to turn the car off so i pushed in the clutch to get the car to stop pulling but didn't disengage.then something blew (thought my engine) because i heard something hit the fire wall plus i seen royal purple on the ground. It basically went past red line as if there was a massive intake leak.So in those few sec i cut the car off and it coasted to a stop.i got it towed home and the next day i tried to see if it would at least start because it was running when i turned it off.( figured if it was blown i had to rebuild anyways) It basically acts as if i turned the car on with my foot in WOT so i cut it off check my oil pan, no shavings or anything check for vacuum leaks with EGR, check for throttle body leaks, and wasn't stuck, nothing. i don't know what hit the firewall because there is no hole in the block and everything is on the car. I don't even know where to start on finding the problem i checked everything i thought would help but no answers.

Sorry about the long post just wanted to give as much information as i can about the problem, please don't flame :bowdown, and Thank you for taking time to read

So let me get this straight - when you turn on the car, it behaves like it's WOT? And you haven't found any vaccum leaks? Nor is the TB valve/line stuck open? How are you checking for vac leaks? Your engine is getting plenty of atmosphere, and there's only so many ways for that to happen - through the TB, the intake mani (mani gasket/EGR/vac lines loose).

What are your vacuum readings at idle? And if you do not have a vac gauge, get one.

Your problem with only have 1,3, and 5 is likely to be a clip securing the shifter cable to the bracket on the trans.

I had checked the cable clips and all of them are secure.After the incident there are no gears. I haven't started it up to get a vacuum reading because i don't want it to blow.But it was a little under
-20 on my boost gauge right before the incident. The egr block off seems secure im going to get new gaskets for the throttle body and EGR delete and see if that fixes it.

Lets put the transmission issue aside and try to diagnose one thing at a time. If the car idles at high RPM's, like Ez said, there are only a few things it could be, the most likely of which is a massive vacuum leak.

You never answered Ez's question. How are you testing for vac leaks? Did you make a boost leak tester and pressurize the system? That is the first thing you need to do to determine if air is escaping from somewhere. Judging by the fact that you said idle acts is if the car is at WOT, if it is in fact a vac leak it will be very easy to determine where air is escaping.

If its not a vac leak, are you absolutely sure that your TB is operating correctly? Butterfly plate is fully closing, IAC is operating normally, etc?

My guess is that if you hit 35psi, then heard something hit the firewall, and then this issue began, you likely blew a fitting of some sort off the intake manifold which in turn hit the firewall and is now causing a massive vacuum leak. Check all the IM fittings as well as all fittings on the TB.

I had the same problem with a different setup though but check your fuel pressure if its to high it will cause that problem.

If you looked around and found nothing missing in the engine bay, I'm willing to bet the knock you heard was the throwout bearing, fork, or clutch pieces thrown around in the bell housing. Not that this solves your idle problem but, why don't you peek through the rubber boot on the clutch slave cylinder and flash light in there. (boot covering the fork rather)

yea the clutch is fried so is the trans. The best thing i can think of is that i am going to just rebuild get pistons, and rods checked etc... and possibly buy an intake manifold from all motor mike from the neon forums and go from there.

Originally posted by kayd28eclipse
... and possibly buy an intake manifold from all motor mike from the neon forums

Psst, he's on here too.

I had my car hooked up to a SNAP ON scanner last winter and it was doing that same thing, revving to almost redline. The TPS voltage was climbing like the pedal was being pressed, I was never able to figure out why it happened before switching manifolds with the new engine. Also, my egr was on back then and by unplugging it the idle dropped.

It may be me just chasing ghosts but I figure I'd offer that, maybe you have a scanner at your disposal after the rebuild to see if something similar happens.

great build btw, I'm surprised you were able to get a downpipe in there, was that a stock GS-T pipe?

also may want to check your TPS.

knock noise sounds like one of the fittings in the back of the intake. wacked out tps + major vacuum leak= zoom zoom zoom

just my .02
good luck