Is the check engine light ( PGM-FI ) light on the dashboard came on? There is a ECU ( computer ) under the passenger seat. Count the number of red LED light flashing. Usually it is the oxygen sensor problem if you see 1 light flashing. If there is not check engine light, do tune up and if that does not fix the problem, check the catalytic converter.
1) Remove hazard fuse at the positive battery terminal for 10 seconds to reset the ECU. 2) Warm up the engine until the fan comes on. 3) Check the check engine light. 4) If the check engine is on, check the fuel pressure at the fuel filter. The pressure is between 36-41 psi. If low, replace the fuel filter. If high, replace the pressure regulator. 5) If pressure is O.K., disconnect the O2 sensor from the wire harness. Warm up the engine. 6) Connect digital multi-meter between the wire terminal of the O2 sensor to ground and measure the resistance with engine running. 7) The voltage should be 0.6 volt at wide open throttle and below 0.4 V at the idle. Seems like the voltage reading is little out of spec during idle.
On my 1987 Integra, emission failed but the check engine came on when driving. I think the HC was too high. Replaced O2 sensor and the emission reading is now very low and passes emission every year afterwards.
1) Remove hazard fuse at the positive battery terminal for 10 seconds to reset the ECU. 2) Warm up the engine until the fan comes on. 3) Check the check engine light. 4) If the check engine is on, check the fuel pressure at the fuel filter. The pressure is between 36-41 psi. If low, replace the fuel filter. If high, replace the pressure regulator. 5) If pressure is O.K., disconnect the O2 sensor from the wire harness. Warm up the engine. 6) Connect digital multi-meter between the wire terminal of the O2 sensor to ground and measure the resistance with engine running. 7) The voltage should be 0.6 volt at wide open throttle and below 0.4 V at the idle. Seems like the voltage reading is little out of spec during idle.
On my 1987 Integra, emission failed but the check engine came on when driving. I think the HC was too high. Replaced O2 sensor and the emission reading is now very low and passes emission every year afterwards.
Answers & Comments
Is the check engine light ( PGM-FI ) light on the dashboard came on?
There is a ECU ( computer ) under the passenger seat.
Count the number of red LED light flashing.
Usually it is the oxygen sensor problem if you see 1 light flashing.
If there is not check engine light, do tune up and if that does not fix the problem, check the catalytic converter.
1) Remove hazard fuse at the positive battery terminal for 10 seconds to reset the ECU.
2) Warm up the engine until the fan comes on.
3) Check the check engine light.
4) If the check engine is on, check the fuel pressure at the fuel filter.
The pressure is between 36-41 psi. If low, replace the fuel filter. If high, replace the pressure regulator.
5) If pressure is O.K., disconnect the O2 sensor from the wire harness. Warm up the engine.
6) Connect digital multi-meter between the wire terminal of the O2 sensor to ground and measure the resistance with engine running.
7) The voltage should be 0.6 volt at wide open throttle and below 0.4 V at the idle. Seems like the voltage reading is little out of spec during idle.
On my 1987 Integra, emission failed but the check engine came on when driving. I think the HC was too high. Replaced O2 sensor and the emission reading is now very low and passes emission every year afterwards.