Hello all, I have a 93 5.7 with 161K on it and it failed emissions for hydrocarbons too high at idle. At 2500 rpm it passed ok. Truck runs pretty good but has only been driven 5-7000 miles in last 5 years. It doesnt run rich or have any odd odors and the cat temp is only 50 deg difference front to rear so it seems to be flowing ok. I know it needs a tune up since it has probably been 7-9 years. Besides the tune-up and timing set, is there anything else I should be checking for? Appreciate any help I get. Thanks