94-22re runs rough at driving speeds

[ger]

Hi all,
New here.
I have a 1994 22re pickup that is having the stutters at the higher rpms.
I have replaced the following:
Air cleaner
Spark plugs
Spark plug wires
ECU modulator
O2 sensor after the catalytic converter, did get a check engine with this one.
Not much left to change.
No check engine light shows now.
I did some vacuum checks, while the engine is running at high rpms and stuttering i can pull
the vacuum line to the EGR valve and everything smooths out.
I'm about to change some or all orf the vacuum lines, but they all seem to be OK.
I did the idle speed check on the EGR valve with vacuum and the engine dies like it say in the Haynes manual. I ohm sifted the three vacuum switches on top of the engine, they all
read the same, about 35 ohms.
I've run out of ideas. Any suggestons?

ger

[qsd-dan]

"I did some vacuum checks, while the engine is running at high rpms and stuttering i can pull
the vacuum line to the EGR valve and everything smooths out."

I think this is your problem right here. Remove the vacuum line to the EGR and plug it (I use golf tees). Drive it around (even for a few days). If the problem disappears, then you narrowed the problem down. How is your idle? Usually a crappy idle is the result of an EGR valve stuck open. 1994 gets a little more complicated than I'm familar with (mine is 84), but either the problem is the EGR, EGR modulator, or the BVSV valve. Also, check the vacuum lines between all of these devices. Good luck.

[ger]

Idle seems perfect. The problem starts after a few minutes when the temperature
kicks in one of the vacuum switches.
Also found some exhaust leakage around the catalytic converter, input side and
output side. Going to check into this today.
Thanks for the response.