Honda Repair Questions? Ask a Mechanic for Answers ASAP
if you're smelling exhaust fumes then I'd start by checking all the exhaust joints - where the manifold joins the head and the down pipe joints just before the catalyst - the best way to do this is to start the engine from cold and feel around each joint with your bare hands - feeling for exhaust gas blowing over your fingers - you'll have about 30 seconds before it all gets too hot.
also check the condition of the EGR valve where it feed the exhaust gas back into the intake manifold
Start by checking the connections to the EGR valve, if either the vacuum pipe of electrical connection are damaged / corroded then the EGR can be on all time which certainly will hurt performance. Its also possible that its a fault with the EGR valve so its worth removing the valve and cleaning it out with brake cleaner, if it looks particularly clogged then replace it.