Happened yesterday morning, at startup, CEL light came on, car sounded fine though. However, when 3 bars were reached, the started started idling between 1000 and 1500 RPM. It would go up and come down continously. Took it in to Honda, the diagnosed it as one of the exhaust valves malfunctioning. However, the problem is intermittent. Told me to pick it up, and bring it back if any problems. As soon as I pick it up, the same problem occurs, so I just left it there for them to take a look at on monday.

Can anyone chime in with a possible cause, and or fix for this. Any information appreciated.

Fed.

 

Sounds like BS to me. Is this just a guess that they made, or did they pull the codes from the ECU? Does the engine drive normally? I would suspect the MAP sensor, throttle sensor, or electronic air control valve.

 

I agree with Gernby in that you would not detect an exhaust valve malfunction by OBD-II code (to my knowledge anyways). A PO300-PO304 code, which indicates a misfire by the way, might be interpreted as an exhaust valve problem.....but you indicate that the problem specifically occurs at 3 bars. By the way three bars is meaningless and should only be used as a reference point as it occurs at roughly 158 degrees....which is when the OBD-II diagnostic registers that your car has officially "warmed" up. To know your officially there you need either a PGM scan tool or OBD-II Explorer Software and a laptop. All that being said I would make sure your dealer has the capability to pull "temporary DTC's". Specifically I would suspect you will find an error code P0410. This would indicate a problem with your secondary air pump circuit. May be the Air Control Solenoid Gernby noted (if you have recently installed a CAI), or more likely per your described problem your pump simply crapped out on you. You may have just gotten it wet and blown the fuse. This fuse is located under the hood in the auxillary fuse box (should be labeled AIR PUMP). It is a 60 amp fuse. This fuse box is located on the drivers side under the hood. You'll find it midway between the front spring tower and the brake fluid reservoir on the inner fender well of the drivers side. Open the plastic cover and the Air Pump fuse is located dead center. I would check this fuse first, if bad, replace. If good then have the dealer pull all "hard" and "temporary" codes. The post your results here.

Utah