Honda Civic A/T D16Y5 1.6L Poor Fuel Economy
#1
Honda Civic A/T D16Y5 1.6L Poor Fuel Economy
Dear Members
i hope you are well, i would like to seek your opinion and suggestions upon the following matter:
I have 1999 Honda Civic A/T with D16Y5 1.6L engine.
since beginning i have been facing with the problem of poor fuel economy and did following in this regard but no use:
1. Changed spark plugs
2. Complete engine tuning incl. throttle body service
3. Oil change (LM 10W40 MoS2)
4. LM Ceratec
5. Replaced Fuel injectors
6. Wiring check
currently it is giving around 6~7 KM/L in city and around 10~11 KM/L on highways
Please help and guide me in this regards what can be done to improve the fuel economy, is there anything that i am missing
i hope you are well, i would like to seek your opinion and suggestions upon the following matter:
I have 1999 Honda Civic A/T with D16Y5 1.6L engine.
since beginning i have been facing with the problem of poor fuel economy and did following in this regard but no use:
1. Changed spark plugs
2. Complete engine tuning incl. throttle body service
3. Oil change (LM 10W40 MoS2)
4. LM Ceratec
5. Replaced Fuel injectors
6. Wiring check
currently it is giving around 6~7 KM/L in city and around 10~11 KM/L on highways
Please help and guide me in this regards what can be done to improve the fuel economy, is there anything that i am missing
#2
I like the tuna here
Re: Honda Civic A/T D16Y5 1.6L Poor Fuel Economy
That does seem low. For those of us in the US, that's about 16.5mpg city/ 23.5 mpg highways in freedom units. What did the "complete engine tuning" entail? Did you change the distributor cap and rotor as well as spark plug wires and fuel filter?
#4
Re: Honda Civic A/T D16Y5 1.6L Poor Fuel Economy
After pulling CEL codes, you forgot to change your fuel filter. That is part of a tune up and can have a serious impact on fuel economy as I learned with my wife's car.
Her mpg was down in the 24 MPG range, changed the filter only and now her economy is in the 33 MPG range.
Don't ask me why it has such an impact, I just saw that it does.
Her mpg was down in the 24 MPG range, changed the filter only and now her economy is in the 33 MPG range.
Don't ask me why it has such an impact, I just saw that it does.
#5
Re: Honda Civic A/T D16Y5 1.6L Poor Fuel Economy
No I did not change plug wires and dist. As mech said these were fine
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#8
Honda-Tech Member
Re: Honda Civic A/T D16Y5 1.6L Poor Fuel Economy
The other thing that happened was the distributor was faulty. Even though the spark timing was adjusted, the sensors built into the housing were failing. That caused a lack of fuel economy as well.
One more to check is the main catalytic converter, make sure it's not plugged.
#9
Re: Honda Civic A/T D16Y5 1.6L Poor Fuel Economy
There's one thing that can cause this is the primary o2 sensor. I have your engine (D16y5) and I never got a CEL ever for the bad o2 sensor. When I finally gave up on the ecu telling me anything, I broke out the multimeter and began testing the o2 directly. Yup, it was bad! I replaced it and my fuel economy numbers shot back up! So much for the CEL actually telling me something wasn't working!
The other thing that happened was the distributor was faulty. Even though the spark timing was adjusted, the sensors built into the housing were failing. That caused a lack of fuel economy as well.
One more to check is the main catalytic converter, make sure it's not plugged.
The other thing that happened was the distributor was faulty. Even though the spark timing was adjusted, the sensors built into the housing were failing. That caused a lack of fuel economy as well.
One more to check is the main catalytic converter, make sure it's not plugged.
How did you test it with multimeter? What reading should it show?
#10
Honda-Tech Member
Re: Honda Civic A/T D16Y5 1.6L Poor Fuel Economy
But I did look up in the service manual for yours and on the plug side of the primary o2 sensor, the ohms should read 10-40ohms between terminal 3 and 4. These are the ones at the bottom of the plug when the connector ring is at the top.
Someone might know where to get the Civic Service manual, and probably a simple google search can find it. You'll need this. It's in pdf form now.
It will also show you how to test the sensors on your distributor. But all should be between 700-1000ohms. The service manual conveniently forgot the d16y5's distributor specs, which is the Hitachi distributor. The specs they're showing 350-700ohms is for the TEC distributor! Took me a lot of digging to find the correct info.
#13
Re: Honda Civic A/T D16Y5 1.6L Poor Fuel Economy
I was testing the ohms of the sensor I got infinity when I tested it, that right there showed it was bad. The a/t version of the d16y5 engine has a four wire primary o2 sensor where mine (m/t) has a wideband 7 wire, different.
But I did look up in the service manual for yours and on the plug side of the primary o2 sensor, the ohms should read 10-40ohms between terminal 3 and 4. These are the ones at the bottom of the plug when the connector ring is at the top.
Someone might know where to get the Civic Service manual, and probably a simple google search can find it. You'll need this. It's in pdf form now.
It will also show you how to test the sensors on your distributor. But all should be between 700-1000ohms. The service manual conveniently forgot the d16y5's distributor specs, which is the Hitachi distributor. The specs they're showing 350-700ohms is for the TEC distributor! Took me a lot of digging to find the correct info.
But I did look up in the service manual for yours and on the plug side of the primary o2 sensor, the ohms should read 10-40ohms between terminal 3 and 4. These are the ones at the bottom of the plug when the connector ring is at the top.
Someone might know where to get the Civic Service manual, and probably a simple google search can find it. You'll need this. It's in pdf form now.
It will also show you how to test the sensors on your distributor. But all should be between 700-1000ohms. The service manual conveniently forgot the d16y5's distributor specs, which is the Hitachi distributor. The specs they're showing 350-700ohms is for the TEC distributor! Took me a lot of digging to find the correct info.
i am blank now !!
#14
Re: Honda Civic A/T D16Y5 1.6L Poor Fuel Economy
#15
Honda-Tech Member
Re: Honda Civic A/T D16Y5 1.6L Poor Fuel Economy
hahah is right! (at what RonJ said).. lol.. I won't spoil the surprise, you can tell us the obvious of what you've determined now of what's wrong with your car..
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#21
Re: Honda Civic A/T D16Y5 1.6L Poor Fuel Economy
x2
I was going to ask this same question. Since it's already asked, I will expand on the question and ask..... Do you know how to verify that the CEL bulb works?
If you can answer that question, you can answer all the previous questions about the CEL.
I was going to ask this same question. Since it's already asked, I will expand on the question and ask..... Do you know how to verify that the CEL bulb works?
If you can answer that question, you can answer all the previous questions about the CEL.
#22
Re: Honda Civic A/T D16Y5 1.6L Poor Fuel Economy
#24
Re: Honda Civic A/T D16Y5 1.6L Poor Fuel Economy
appologies for the late reply ! i verified tha the CEL Works by removing various sensor clips like MAF, MAP, Vtec Solinoid etc and CEL comes on ! but it is quite unusual that there is no CEL where o2 is completely missing
#25
Re: Honda Civic A/T D16Y5 1.6L Poor Fuel Economy
Also post pics of your engine bay. Do you have a 99 Civic HX with the CVT?
So what codes did you pull after unplugging the sensors? Post them.
but it is quite unusual that there is no CEL where o2 is completely missing
Post pic of this area: