I have 02 accord 4 cyl vtec. I have problems starting it and when it does it idles high and low. Also the cat turns bright red and I get a p1399 dtc code. I changed spatk plugs, wires cap and rotor and still same problem. What could be the cause.

You need to immediately replace the Ignition Control Module (ICM) and coil, located inside the distributor. Apply silicone heat transfer compound to the back of the new ICM.

Because of the failing ICM and coil, raw fuel is building up in the catalytic converter. Besides glowing, you run the risk of blowing the exhaust system off the car.

P.S. Be sure to only use full synthetic engine oil (e.g. Mobil 1) in your VTEC.