My 245 has 270000 miles on it running good,failed the Pa emissions.CO LIMIT 01.10-TEST 4.07 FAIL,HC LIMIT 0275 TEST 494 FAIL,NO LIMIT 03600 TEST 1009 PASS.Humm after this I cleaned all the junk of the throttle body,it was nasty.Replaced spark plugs,air filter,change oil,replace distributor cap and rotor.Pulled out air valve and cleaned it also,allso cleaned the AMM with amm cleaner from CFC,good stuff.2th test CO LIMIT 1.10-TEST 0.32 PASS,HC LIMIT 275 TEST 175 PASS,NO LIMIT 3600 TEST 3505 PASS. Hummm I pass this time ,the NO came up some?Allso replaced back brakes cost in parts about 45.00 bucks,also I pull the small hose off the manifold,that came from the flame trap .Got an can of Berryman's B-12 Chemtool ,Cost about 4 bucks,.I put the hose in the can and ran up the RPMs,this will clean off the top valves,and pistons and inside of the intank manifold.