99 cutlass
I've been battling the P0401 EGR flow insufficient trouble code off and on for several months now. Around Thanksgiving my brother in law and I removed the EGR valve and he shot a couple spurts of air from a CO2 canister into the passage leading to the intake to clear the carbon that was clogging it - apparently that was a temporary solution because the same code came back. I've heard in several places that if I remove the throttle body, I can access the passage from the egr valve to the intake manifold - is this true? Would I have to remove the hoses and cables on the throttle, or will there be sufficient room to just unmount the throttle body from the intake? I would rather do this than remove the whole intake manifold. . . Also, will the gasket between the TB and intake necessarily have to be replaced? I guess it would probably be a good idea to replace that anyway as long as I'm in there right? Thanks for any help anyone can give me!

 

I know on the 3.4 and 3.8 GM engines, the TB can be removed pretty easily. I don't remember if the EGR passage is accessible or not though. The throttle cables can remain attached, but they are easy to remove also, they just clip into the throttle cam.
I would replace the gasket, but they are reusable and lots of people reuse them with no problems.

 

Thanks for the reply - I removed the air intake duct today as well as the bracket for the accelerator/cruise cables, and then I unbolted the throttle from the intake, but when I went to remove it, it wouldn't budge! There's only one bolt and one nut that hold the throttle to the intake (according to the Haynes manual) and I removed both of those, but it was still stuck as if I hadn't even touched anything. Is it just stuck to the intake from years of not being removed? The last thing I want to do is force it and break something. . . It looks like it slides up to remove it rather than away from the intake - does anyone have experience removing this?