Intake manifold was cracked. The car did not overheat as I was close to my destination. I disconnected the battery and then replaced intake manifold with upgraded part with aluminum crossover and built in gasket. Also replaced the o rings on the fuel injectors. Checked over my work carefully and finally reconnected the battery. The car was running smoothly before the repair. After reassembly the car misfires at idle on cylinders four and eight. They do not appear to be firing at all. Swapped plug and injector with known good part. Also swapped with known good coil. All this had no effect. Code reader only states that the injectors are misfirng.