It was time to smog and it turned out very bad
Last year bone stock my 91 conv. passed.
Since than I installed:
K&N cone filter
Performance Header
High Flow Cat (cheapy from muffler shop!!!!)
Open exhaust

15mph
HC: 955!!!!!! failed
CO: 1.02 failed
NO: 718

25mph
HC: 878!!!!!!!! failed
CO: 0.74 failed
NO: 732

I suspect that the cheapy highflow cat just can't handle the exhaust heat and is blown.
The plugs and cat had 5-7k on them.

Before I swap the cat to a stock one I don't have anymore (stupid me) I want to get advise from you guys.
Thanks much

 

First culprit is the cat. Do you still have the air pipe that runs to the cat? If that's removed/disabled, you'll have problems.

Dale

 

another plug pic

 

another plug pic

Yes the air pump is connected.

 

The plugs look normal to me for that many miles. You shoulda changed them before though.

Check some basic things. At idle take the dump hose off the acv and see if its dumping air overboard. You'll get some blowby, not much. As it idles, hold your hand over that exaust port and reach over to the BLUE solenoid and disconncect it. The air flow out the dump should increase dramatically. If its blowing and going from the git go write back. What I call the dump hose is the large one at the bottom of the acv that is approx half inch in dia and goes fwd to a silencer under the r/h fender.

The man was asking in the other post about the split air hose at the rear of the intake manifold that follows the exaust pipe and enters the cat . That pipe is approx three eights inch dia, give or take.

The reason your checking the dump hose in the first para is to assure yourself that the air from the airpump is going to the PORT AIR located in the exaust diffusers and when you step on the pedal that it is also going to the split air pipe described above, that forces air into the cat directly.

Put your timing spot on the marks.

Make sure the tps is spot on.

 

Thanks Hailers
I will check all that tomorrow