98 rodeo - engine speed drops to idle while driving

have a 98 rodeo, with a V6 & Auto trans. have an intermittent problem - as I am driving engine will occasionally drop to idle speed and then pick back up to driving speed. Engine keeps running smoothly, just at idle speed.

CEL does not come on / no codes
Replaced Throttle Position Sensor - and thought I had found the problem, but since it is so random, it just didn't happen again for 1 1/2 weeks.

Anyone else have this issue?
Suggestions?

very odd since the throttle is just an old cable style ...

"very odd since the throttle is just an old cable style ..."

That is what I thought, Amigo-2k. That is why I thought maybe the TPS was not reading the open throttle and not telling the computer to give it more gas. But, apparently I was wrong. lol

Update
I cleaned the Mass Air Flow sensor & replaced the fuel filter.
Still no solution....

clogged converters??

clogged converters??

Ooooo.... that doesn't sound good. Is there a way to tell for sure without replacing them? Do any of the Catalytic Converter cleaners really work?


ALSO, I checked the fuel pressure at the fuel rail. 50psi with vacuum hose disconnected from fuel pressure regulator. 37psi with vacuum hose connected. Pressure regulator was replaced just over a year ago.

Ooooo.... that doesn't sound good. Is there a way to tell for sure without replacing them? Do any of the Catalytic Converter cleaners really work?


ALSO, I checked the fuel pressure at the fuel rail. 50psi with vacuum hose disconnected from fuel pressure regulator. 37psi with vacuum hose connected. Pressure regulator was replaced just over a year ago.


I actually took mine to Mineke Muffler and they checked it for free. The can check the back pressure. Mine had a left clogged converter and it would slow down to 40 mph on a hill. You could also hear a louder noise coming from the air box (air filter housing) when giving it the gas.

Thanks, I'll give that a check.