My '94 4runner has developed this issue (not always mind you) that when I start the engine the idle will hunt around the 200-500rpm range and it will quite often stall if at a standstill and I'm not giving it revs. After a few minutes driving the issue will disappear and the truck will go back to riding fine. I've been told this could be caused by the egr, either needing to be cleaned or replaced. Is this the main cause or could it be something else? And left unfixed could it cause more issues? I got a quote from a mechanic in the area to clean the three components of the EGR for 100-150, I don't have the necessary tools to do it myself but have seen what needs to be done in the service manual, is this a bit steep?