Net Seven

iTrader: (5)

I just redid all the stuff around the engine block... I ported the intake manifold, did TB mod, new vacuum hoses, and blocked off the EGR on my 87 sport NA. I got it running, the idle was at 3-4krpms, I was like damn and decided to take it for a drive anyways. I got back my exhuast was making funny noises. I pop the hood look around the o2 sensor and its RED, then under the car the cat is RED. What do you guys think is wrong?

1987RX7guy

iTrader: (3)

I think your cats are probably clogged.

Net Seven

iTrader: (5)

All the sudden they become clogged after I do this stuff? Why is my idle is high up?

1987RX7guy

iTrader: (3)

A high idle could be caused by a vacume leak dude. Maybe I am wrong about the cats but it souns like it I mean the EGR is for emmisions is it not. IT is just my oppinion but look for the vaccume leak that is proly the reason for the idle being so high. You can adjust idle speed by turning the screw on the intake, that might help.

Net Seven

iTrader: (5)

So your saying the exhuast manifold would also glow red if the cats are clogged?

1987RX7guy

iTrader: (3)

I have never seen a glowing exhaust but that is what almost everyone says happens when your cats are clogged. Perhaps the manifold would glow because of the heat being retained by the cats and it just builds up. What was your idle before you did this stuff.

Net Seven

iTrader: (5)

My idle used to be perfect around 800rpms. and never before did my cats glow or anything like that.

1987RX7guy

iTrader: (3)

Look at all the vac hoses and check they are on right. Also does the EGR have any vac hoses connected to it if so you should have blocked them off or put them somewhere else. Double check everything make sure that everything is on right. My car started to stall after I eliminated my pulsation damper because I forgot to tighten some bolts on the black plastic piece that connects the rubber hose to the intake and that was a very bad vac leak.

Bigretardhead

when you port the intake manifold, it makes your car pollute more, so this could have clogged the cats.

spray carb cleaner around everything that has to do with vacuum(while the car is running), and if the idle goes up or cahnges pitch or whatever, theres a vacuum leak(in case you didn't know).

Net Seven

iTrader: (5)

Well i just started it up to move the car, and the rpms went up high. Then they came down and the car tried to idle normal, but was having trouble and almost dieing. Could clogged exhuast cause this too?

dr0x

Maybe. Porting all that stuff could also make the idle rough. Try readjust the TPS?

Net Seven

iTrader: (5)

Nope havent adjusted the tps yet, but would tps cause an idle like this?

NeilTII

my cat got red hot (almost white!) and I just let it cool down and took it off and hollowed it out. Now no more red cat.

Audiofight

HOL-LOW-THEM
HOL-LOW-THEM

No more cats makes the rotary happy!

Aaaaahhhhh..............free breathing, no more stinkin' cats!

Seriously, gutted mine and the exhaust sounds nicer and the car performed all-around better.

Net Seven

iTrader: (5)

will there be enough back pressure to open the 5th and 6th ports though?

Ni5mo180SX

Sounds like you have a vacuum leak. Check any areas which may have crossed your mind while reassembling.

Net Seven

iTrader: (5)

Tomarrow ill be gutting them!! and ill adjust my tps and see how everything is.

dr0x

A vacuum leak wont cause a cat to glow red. Seriously, a precat probably let go and clogged the main one.

gsracer

heh what a great oxymoron

Spraintz

iTrader: (1)

have more flow but the exhuast will stink, and if you have stock mufflers can sound kinda gross and loud.

good luck, have fun

Scott 89t2

the idle always goes up after doing the TB mod. reajust it using the screws on the TB.

vicious525E

seriously it's your cats, thats why your exhaust is red, just take the longest screw driver you can find and just poke that **** out, the cats get clogged easy on any rx(even na's), hell they get clogged even with all the emitions **** on them, just take off your cat and get that crap out and then see what happens, but im pretty positive that it's a clogged cat, my TII's exahust got extreamly hot when i took the belt off my emitions pump so i did that and no more realy hot exhaust...

Josepi

If you do decide to gut them, please wear some form of breathing mask. You SERIOUSLY don't want to breath the dust.

MaxRX7

If you still had the cat. converter you shoulf of left the EGR alone, since you blocked it off that cause the cat(s) to glow red. so if you don't have emissions you can put on a straight pipe and not have to worry about it and just adjust your idle. if you have emissions put back the EGR valve.

Net Seven

iTrader: (5)

You guys think its fine to just gut all the cats? Like the pre-cats, and the main cat? I was reading about it and some people said that gutted cats can blow up or something like that.

There will be enough back pressure for the 5th and 6th ports to open right? They are very easy to move and open. I just tested them with an air compressor and they open with very little pressure and hold it very good. They dont even start to go down while the pressure is in there, then when it is released they go down.