I have 95 honda accord ex did tune up pcv valve rotor cap dist cap plug wires and i put e3 plugs ran royal purple fuel treatment and half way through tank started to idle rough and running rich. After about 20 min of running but if i shut off let it sit 5 min it will start running fine then after a few minutes it will start running rough again

 

Check engine light? What codes?

good luck

 

No check engine code just srs code

 

Running smooth on cold start, and warmed begins to miss suggests a possible fuel mixture problem. This will usually set a code for lean or rich condition.

An advanced scanner w/ data monitoring is necessary to explore fuel trims and perhaps a clue to problem.

Make sure spark plug wires are routed correctly.

good luck

 

If the plug wires were crossed it would run horribly at all times right from the start.