2005 Honda CRV Fuel economy

CARMANMT

MEMBER
2005 HONDA CRV
4 CYL
AWD
AUTOMATIC
19,500 MILES

Hi, I have a HondaCRV and it was averaging 22 to 23 mpg and recently it has slipped to around 19 with the same driving conditions. I replaced the air filter, no check engine light, just seems odd that it would lose fuel economy like that, although not a lot, but it is noticable. I live in the Philade;phia suburbs, so was thinking it could be the winter fuel mixes here, but it didn't do it last year.

Anyone ran into this before? Someone told me to reset the computer, but not too sure if I want to mess with that.

Any suggestions would be appreciated.

6 Replies

KHLOW2008

MECHANIC
41,814 POSTS

Hi carmanmt,

Resetting the PCM is not going to do any good.

I would suggest doing a tune up. Check the spark plugs, clean the throttle body and IAC valve and check ignition timing.

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Tuesday, November 25th, 2008 AT 7:26 AM

CARMANMT

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19 POSTS

I checked the plugs and they appear ok. Cannot locate the IACV so if you know where that might be I could use a little help and not sure if the timing can be adjusted on these newer engines.

Thanks much.

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Thursday, January 1st, 2009 AT 8:43 AM

KHLOW2008

MECHANIC
41,814 POSTS

Hi carmanmt,

HAPPY NEW YEAR.

No, ignition timing cannot be adjusted but it would give you an idea if anything is amiss, a fluctuating mark would mean the PCM is constantly tying to compensate.

After noting your mileage and doing additional research, if you are having idling speed fluctuations or erratic idling, then a computer relearn procedure might help.

PROCEDURE

1. Make sure all electrical items (A/C, audio, rear window defogger, lights, etc.) Are off.

2. Reset the ECM/PCM with the HDS.

3. Turn the ignition switch ON (II), and wait 2 seconds.

4. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, or until the engine coolant temperature reaches 194 °F (90 °C).

5. Let the engine idle about 5 minutes with the throttle fully closed.

NOTE: If the radiator fan comes on, do not include its running time in the 5 minutes.

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Thursday, January 1st, 2009 AT 3:56 PM

CARMANMT

MEMBER
19 POSTS

KHLow2008, thanks I did the proceedure and will let you know the results.

HAPPY NEW YEAR.

No, ignition timing cannot be adjusted but it would give you an idea if anything is amiss, a fluctuating mark would mean the PCM is constantly tying to compensate.

After noting your mileage and doing additional research, if you are having idling speed fluctuations or erratic idling, then a computer relearn procedure might help.

PROCEDURE

1. Make sure all electrical items (A/C, audio, rear window defogger, lights, etc.) Are off.

2. Reset the ECM/PCM with the HDS.

3. Turn the ignition switch ON (II), and wait 2 seconds.

4. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, or until the engine coolant temperature reaches 194 °F (90 °C).

5. Let the engine idle about 5 minutes with the throttle fully closed.

NOTE: If the radiator fan comes on, do not include its running time in the 5 minutes.[/Quote]

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Wednesday, January 7th, 2009 AT 4:52 PM

CARMANMT

MEMBER
19 POSTS

Hi, I checked my mileage after the reset and I got 23.5, 21.3 and 21. Maybe that is it. I'm just going by the rating of 22 city, 28 highway. My commute is 25 miles each way 7 of which is local then the remainder is turnpike.