This is in a 95 Tahoe but I figured it wouldn't hurt to ask.
I recently changed the ac compressor and noticed a line running to the egr was unplugged. I plugged it back in but broke the line running from the TB to the EGR solenoid? The truck had a vacuum leak but still ran alright.

The truck would also throw a check engine light when driven at a constant speed for 15-20 minutes which I would imagine came from the EGR vacuum line being disconnected.

Well tonight I changed that broken line and now when I let off the accelerator the truck stumbles and bogs down to like 300 RPM. Other than that the motor doesn't show any sign of sputtering or missing. Can the EGR be the issue? If I unplug the solenoid and cap the vacuum lines would that be a way to tell?

 

If you take vacuum away from the engine, the engine will bog like hell from lose of vacuum at idle. Thus meaning the EGR could be clogged, or something could come up in through the DLC. Check the code it gave and go from there.

 

It isn't throwing a code right now.

The way I see it, the original code was from the EGR being unplugged from the EGR itself. Believe it or not, it ran better with the vacuum leak from the solenoid to the TB than it is running with everything hooked up. I kinda figure the EGR is stuck open and forcing air in when I let off the gas; sending the mixture through the roof and leaning out.

However I'd like more opinions since I am not very good with any "newer" (god I'd hate to say it but all I have any understanding for fixing is HEI carbed motors) technology.


If I cap any EGR related lines at the source of vacuum, would this be a way to tell if the EGR or solenoid is the issue?

 

Egr doesn't send air back into the engine, remove the egr & make sure it not stuck open. The egr valve should never get vacuum at idle.