You can get plugs for the manifold & lowe's, home depot, ace hardware, ect. The plugs are NPT pipe thread if I remember correctly, just bring one of the old fittings for comparison.

 

Unlikely. Look at the tubes and tube nuts that come OUT of the exhaust manifold--and the threaded holes in the manifold. I bet they're inverted-flare fittings, not pipe thread.

 

They could very well be inverted-flare fittings. I know I bought mine at the hardware store in the plumbing dept, which is why I assumed NPT. All I know is they fit & I haven't had any issues with them in the 4 years or so they've been in there. I'm not saying I'm right, I'm saying this is what I did and it worked.

NOTE: Until the plugs are seated you will have to re-tighten them every heat cycle or two.

 

I'm pretty sure that a 91 is still OBD1 , so you have a read only computer so it can't be flashed or overwritten . Some things can be bypassed , like EGR codes on my 88 RS i fixed by putting a ball bearing in the vacuum line just before it goes into the EGR valve , this works because the code was tripped by a vacuum signal that only reads if there is a leak in the line or in the valve itself , for that system no news is good news so blocking the signal was all it took .

 

Anyone know an easier way to remove those damn AIR tubes from the manifolds??

 

Cut the tube off flush at the nut, weld the hole closed. Done.

 

How do you get the AIR tube from the catalytic converter out of the engine bay?

 

I think it is bolted to the back of the heads

 

If some of you need that much help to gut your emissions system...maybe you should reconsider WHY you feel the need to gut your system.

 

I got mine out no problem, just nice to have some insight on easier ways to remove it. Taking it out isn't about adding HP for me, its about allowing for easier maintenance, maybe exhaust upgrades, and an overall cleaner engine bay.

 

Is anyone able to tell me, if I delete the smog air pump and use the delete pulley, will this affect the ERG codes? I have two current issues, one is that a baring in my smog air pump is gone and I can't find a replacement part for the life of me so I think my only option is to remove it and use the delete pulley. My second is I'm getting code 32 ERG so I'm not sure if its because the smog pump isn't working properly or if its something else. The car is difficult to start, taking 2-3 turns but once it does, it runs beautifully with the exception of the squeal from the smog pump and code 32 / SES flashing. I'm pretty new to this and trying to figure it all out. This is for the 1988 corvette. Thank you in advance.

 

Get an AIR pump from the Treasure Yard, and fix the EGR code. The two things are almost certainly NOT related.