97 Tracker EGR Problem

My 97 Tracker has had the check engine light on forever and it keep coming up with the same code (400) and I have changed the egr valve. Also it wants to stall when I come to a stop (not all the time) unless I turn on the ac but it will clear up and not do it for a week or so. Took it to a local repair shop to have it tested and they told me the egr port was stopped up with carbon and need to be cleaned out. I took off the egr one morning and had my son crank it up I had my fingers over the two holes down there and I don't think they are blocked because one hole was blowing out very strong and the other was pulling in very strong. I don't like taking it and paying money for them to tell me BS. Can anyone help? Thanks in advance for any help.

Clean the throttle body with carb cleaner. SHOULD help. There is a small vacum line on top of the engine next to the thorttle position sensor, with the engine running,rev it up to about 2000 rpms, spray cleaner in vac. line. Engine will bog down some, try to keep it running, engine will smoke some also, don't worry. If you can't find the vac. line or don't know which one, just clean it best you can. Hope this helps.

Mine was doing the same thing. I took the IAC Valve off and cleaned it several times with some starting fluid and then blew it out with an air hose. It had some carbon build up in it. When I blew it out with the air hose some of the carbon particles came out.It's been 2 weeks now and still idiling fine. Hope this helps. It has been doing good for the last few months.