cryptonight

Hi, I have a 2001 Chevy Silverado Z71 truck, 5.3 eng, 170K miles.
The engine is running ok but has a minor rough spot at idle and when running (a minor shake). The basic passenger in the truck would not notice it (unless they were a mechanic) but I do because I have owned it since it was new (and I am an amateur shade tree mechanic).

This week I just did the 2nd tune up on it (at 170K miles, plugs & wires only) and I still have the rough spot. The 1st tune up was done at 100K miles. I thought the problem would go away with the new plugs/wires but did not. Now I'm thinking injector or coil? Anyway to narrow it down? Thanks. Steve

country_09

Does it have any codes? Clean the throttle body and air filter as well. Codes would be a good place to start

cryptonight

Thanks. There are no Codes showing and the Air Filter is new. Is there an easy way to clean the throttle body? Never done it.