Hi, I just did a mayor tune up on my 1991 Ls400, spark plugs, wires, cap's & rotor's air filter and fuel filter. I re-checked the firing order and is fine. When I start the car the check engine and track off light goes on and stay on, at idle seem fine and when I step on the gas in park I can feel a misfire at around 2000 rpm or more, when I drive it can't go over 40 mph because it start pinging bad like if it is out of timing. I got the parts from Auto Zone, do you guys think that it may be the cap and rotor. Thank you in advance.