Hi,

I'll start with info on my car.

Honda Civic 2004 EX, 1.7L, 4dr, Auto Transmission
160,000KM

Recent work done:

- I changed the plugs
- I changed air filter
- I cleaned the IAC Valve
- I cleaned the throttle body
- I cleaned the EGR Valve
- Ran injector cleaner through it one time
- Changed the AFR sensor and O2 Sensor
- Changed Timing Belt (125 000 km)
- Reseted ECU and processed to a Idle Learn procedure

- Removed all the HHO parts (reactor, EFIE, ....)


I have a real problem with my car. When the engine is hot (after warmup enrichment phase), the idle is rough when I come to a complete stop, whether I'm parked or stopped at a light. I can definitely feel it vibrating. The engine shake (almost ready to stall) and I can see my exhaust pipe is vibrating quite a bit (more than normal). This is less perseptible on the "P"ark position and amplified one the "D"rive position

I can't feel it when I'm driving. It's OK when the car is cold (durint warmup enrichment step).

When this happens, I noticed that the Short Fuel trim go down to about -15 to -20%. NO CHECK ENGINE LIGHT. The RPM is about 650-750.

Weird: When this happends, If I rev the engine to 3500 to 4000 rpm then the STFT value return to a more normal reading to about +5% to +7% and after that, the engine is OK. the rough idle stop until next time.

When I slowed down, the ECU is in open loop and no problem but when the car is to stop/red light he returned to close Loop and the vibration happend.

To make a test, I purposely disconnect a sensor (AFR sensor) so that the CEL comes on and the computer is in OPEN LOOP. During these two weeks of testing, the rough idle problem never happend.


Other than that, there are no other noticeable problems. The car has lots of power, and gas mileage is normal.

If you can help me, it will be very very appreciate


DATA - TEST #1 (11h53)


DATA - TEST #2 (12h47)