It seems that on my intake, I may be able to take off the manifold cover and access the t-shaped piece (#7 in illustration) that is for the EGR and clean everything in and around that piece.

 

have you tried to run car with highest octane gas ??? if not,, fill up the tank and try it before doing any work on the engine,,,assuming it is engine pinging ...

 

One of the rattling sounds that I see alot of is the sounds of the cat converter pingging and rattling under acceleration load..Any one think maybe ?

 

If the engine "pinging" goes away with higher octane, what would you say the problem is then?

Thank you.

 

I would say this is an option, except that I know my mileage has changed about 3 mpg less. So there is something going on. Plus the rattle is directly related to a specific engine rpm and load. Immediately gone when I release accelerator.

Any other thoughts or ways I can double check the cat rattling?

 

Hit the exhaust heatshield at all kinds of different places to see if you can duplicate the nature of the sound. Sit inside while someone does this, because it'll sound different from inside the car.

The reason it would be caused by a specific speed & load, is that as the engine torques in it's rubber mounts, the exhaust system moves around. When that happens some of the exhaust heat shields might touch something.

 

Jim, I'll give it a try. Thank you very much for the thought.

 

I pulled off the intake manifold cover (#4 illustrated in the image above) and pulled out the EGR lateral diverter (#7 illustrated above) and checked that the passage was clear both laterally and vertically down towards the EGR valve location. It's fairly large passage and it was NOT blocked up whatsoever. Some normal black material, but definitely no blockage from what I could see.

Does anyone know a way to test the EGR valve for proper functionality?

Could any of my symptoms be from vacuum leaks?

Thank you

 

On other models its the individual ports into the intake manifold runners that become blocked. Also sometimes the labyrinth path to the ports can become blocked. The path is apparently designed to provide equal length passages.

good luck