2006 Suzuki Grand Vitara EGR code P401

[Passport1]

My 2006 Suzuki Grand Vitara has a cel code P401, egr exhaust recirculation insufficient. The vehicle starts and runs fine. I've been using 89 octane now to prevent pinging. The engine takes 87 octane. 2.7 V6 mounted fore and aft; rear wheel biased 4x4. Added a bottle of Techron and the engine is on its first dose of Valvoline R&P 5w-30. Uses a bit of oil but no leaks. 155K miles.

The suv sees lots of short trips in town, plenty of stop-'n-go. Rarely gets up to highway speed or WOT. From some of my research an 'Italian tuneup' might fix it. The EGR assembly is located on the back of the intake manifold and is very labor intensive to replace.

Has anybody got suggestions?

 

[wavinwayne]

I fixed this code on an old 1997 Ford Expedition 4.6L by removing and cleaning the intake elbow right behind the throttle body. It was completely caked in black goo that I removed with hand files and sheer will. Not sure if such a thing is possible on this engine.

I had previously replaced EGR valve thinking it was the culprit, but the code remained after clearing it. Only cleaning the elbow of all the gooey carbon buildup solved it.