Hi.
I have a Honda Civic 96 DX / coupe, with 145550 miles.
Recently the check engine light was ON. I reset the light, but after 1200 miles it turns on again.
When I stop in a traffic light the RMP goes down under 1000, around 100 RMP.

I review the motor and found that the exhaust manifold was cracked where the upper O2 sensor is located. The manifold and the upper O2 sensor where replaced but the yellow Check Engine motor is still there. I try to reset it, but ones you turn on the motor, after 5-10 seconds running the yellow light come ups.

I jump the service check connector and receive 5 blinks. I reset the ECU again and disconnect the MAP sensor. Jump the service check again and receive codes 3 and 5. After connect the MAP sensor again just 5 blinks are shows.

I have checked vacuum hoses, pipes and connections. Make sure all connectors are secure. The voltage on the conector is fine = 5 volts.

Would you replace the MAP sensor with out continue to do a lot of test?