Rough idle when warm

I have an 1998 Toyota Avalon with 110,000 on it. The car runs/idles great when first started, but after a few minutes the idle becomes rough and there is a hesitation/chugging when under light acceleration. Heavy acceleration is fine. The car had a full tune-up less than 5K miles ago.

Let me guess a check engine light on? If so take it to shop or hopefully auto parts store to get it read for free and post back.

Yes, the check engine light just came on and I went to an automotive parts store where they used their code reader. The code indicated a problem related to the EGR valve. It was suggested that I remove and clean the EGR valve and see if it fixes the problem, if not replace the valve.

That is sound advice. You should also clean out the exhaust gas passages in the manifold while you have the valve out.

Will do, thanks for the advice. Luckily for me the valve is easy to get at and it should only take a few minutes to remove