MPG is terrible.

[F22Chris]

I'm getting 15 miles a gallon, and correct me if I'm wrong, but that is horrible. All my tune-up crap is up to date, and I cleaned the EGR & passages. I'm going to set timing later because I retarded it for emissions. If I run 2 degrees advanced will that help at all? I've been reading that advancing might net better MPG, if somebody could chime in on that let me know.

[Ralphie]

I can't comment on advancing the timing, but I believe I have heard that before.

Do you have any CEL?

What tune up "crap" did you do?

[F22Chris]

No CEL. Plugs, wires, cap and rotor, fuel filter, oil change, and recent sea foam before the plugs.

[oni_cb7]

How old is your catalytic converter and o2 sensor?

[F22Chris]

Cat is less than a month old, and my O2 sensor was replaced last summer.

[khal.lawson]

Cat is less than a month old, and my O2 sensor was replaced last summer.

Maybe alignment? Leaky injectors? I'm looking into these things now with mine.

[illinois_erik]

how do you set the timing when the ecu changes it on the fly? why not set it properly with the diagnostic plug shorted and leave it alone. check your IAT sensor and see if its not melted on the end. what do your plugs look like? thatll tell you more then trying to outsmart the honda engineers.

[F22Chris]

I was going to set it to 15 and leave it until I read advancing could help. It did cross my mind that the ecu will change it regardless. Just curious because every bit helps. Seems a chip and tune is the only way! And I will read my plugs. Does timing have anything to even do with the mpg?

[illinois_erik]

I was going to set it to 15 and leave it until I read advancing could help. It did cross my mind that the ecu will change it regardless. Just curious because every bit helps. Seems a chip and tune is the only way! And I will read my plugs. Does timing have anything to even do with the mpg?

check the IAT too..that plays a role in the scheme of things, they can be damaged and still not throw a code, you can even throw an ohm meter on it, i just dont have the specs offhand and my main computer is in storage, yes timing can have a good impact on economy. say for example you have it at full swing or whatever the ecu can only adjust so much for conditions, thats why you set the base ignition timing and let the ecu take it from there. lets just say the cd5 has a bent valve or two but the timing is deat nuts and the old lady still gets about 22mpg lol.

[JDMDriver]

Cat is less than a month old, and my O2 sensor was replaced last summer.

You can only rule out the o2 sensor if it is original and japanese brand.

Bosch Ebay stuff and any other brand I do not trust and hear even Bosch does not work.

ONLY original Honda, Denso or Ngk I trust.

[F22Chris]

check the IAT too..that plays a role in the scheme of things, they can be damaged and still not throw a code, you can even throw an ohm meter on it, i just dont have the specs offhand and my main computer is in storage, yes timing can have a good impact on economy. say for example you have it at full swing or whatever the ecu can only adjust so much for conditions, thats why you set the base ignition timing and let the ecu take it from there. lets just say the cd5 has a bent valve or two but the timing is deat nuts and the old lady still gets about 22mpg lol.

I will. So the ECU can only adjust so far? Makes sense so we time it for its optimal ranges. And it's on the driver side lower plenum right? I never thought to check that. That could be causing my warm start misfire too.

[F22Chris]

Idk about you, but this looks fine to me.

[illinois_erik]

Idk about you, but this looks fine to me.

yes it actually looks better then most ive seen..

2) Intake Air, Coolant Temperature Sensor Resistance Value
Temperature（℃） Ohm（Ω）
–20 15000~18000
20 1000~4000
80 200~400

[F22Chris]

Thanks you. We'll see. I looked at the O2 sensor connector, and there was coolant residue on it. One of the smaller coolant lines leaked onto it.

[wagon-r]

If I run 2 degrees advanced will that help at all? I've been reading that advancing might net better MPG, if somebody could chime in on that let me know.

Advancing timing does improve mpg. But unless your timing is severely retarded to begin with, we are talking something in the 2-3% range, or maybe half an mpg at best.

You will only get 15 mpg if you take short trips in cold weather, as it takes a lot of fuel to heat up the engine, especially when it is cold out. But otherwise, yes 15 mpg is horrible.