gettign wuite bad fuel efficienccy... why?

[Mugen_Euro]

hey guys got a accord euro
recent mods include
CT headers
K&N cold air intake system (typhoon)
im pre sur i should be getting better than stcok fuel efficency but instead its terrible?
any ideas. I kno its not the way im driving it as i drove symilar before and had decent efficency, now even a short trip drains a bar or two on the meter
im getting around 300km outa a tank... :(

Edit: Problem Occured BEFORE Headers were installed!

[teh_mechanic]

i cant remember off top of my head but the cold air intake hasnt cut any sensors out has it... theres an air intake temp sensor in the intake piping from stock i think, thats still in there? Other than that another common one is the thermostat being stuck open so car never gets to operating temp. You will tell because it takes much much longer than normal for the car to warm up, should be at about half guage after three or so minutes

[Mugen_Euro]

idnt think its a hose leak i cant hear any leaks when i get a mate to rev the egine... and the fuel efficiency is good wen i rest the ecu but it only lasts a day or two then i c the fuel meter drop alot every time i drive....

[MWAKU]

i cant remember off top of my head but the cold air intake hasnt cut any sensors out has it... theres an air intake temp sensor in the intake piping from stock i think, thats still in there? Other than that another common one is the thermostat being stuck open so car never gets to operating temp. You will tell because it takes much much longer than normal for the car to warm up, should be at about half guage after three or so minutes

can u fix the thermostat if that is the problem? or do u have to replace it?

[aaronng]

can u fix the thermostat if that is the problem? or do u have to replace it?

Cheaper to replace if you have to.

[aaronng]

hey guys got a accord euro
recent mods include
CT headers

I suspect that the primary O2 sensor was damaged when the CT headers were installed. Damaged primary O2 sensor will increase the fuel consumption but it won't give a check engine light!

[Mugen_Euro]

I suspect that the primary O2 sensor was damaged when the CT headers were installed. Damaged primary O2 sensor will increase the fuel consumption but it won't give a check engine light!

hmmm i read up on this in another post about eg's bad fuel consumption. most the ppl thier sed they tried changing their primary 02 censor and it didnt help at all....
but how much wuld it set me back to replace and install?

[aaronng]

hmmm i read up on this in another post about eg's bad fuel consumption. most the ppl thier sed they tried changing their primary 02 censor and it didnt help at all....
but how much wuld it set me back to replace and install?
Your Euro is not an EG though. :p From your reports that the fuel consumption is okay after an ECU reset and then starts to increase after a few days, it points to the ECU getting incorrect information from the primary O2 sensor which then causes the long term fuel trim to skyrocket upwards.

If there is a wrecker near your place, try to get a hold of an O2 sensor from a wrecked Euro (has to be 2003-2008 I believe).

[Mugen_Euro]

hmmm culd be thing is i had this problem befor i got my headers installed, as soon as i put in CAI the efficency went fritz... i figured the headers might make it a bit better btu it didnt help at all....Zzzzzz infact even whe i only had a pod filter and no cAI my fuel efficiency was never beter than 450 / tank but then im a bit of a rev heaf xD
so i dnt think the probl;em is the 02 censor but ill check that out any other ideas?

[GEG]

I suspect that the primary O2 sensor was damaged when the CT headers were installed. Damaged primary O2 sensor will increase the fuel consumption but it won't give a check engine light!

aaronng won't a damaged sensor throw up an CEL? depending on damaged sensor, or wires, etc?

but it would make sense in this case, especially with aftermarket headers.

also, OP, stop typing with your nose, it makes it hard for everybody.

[dougie_504]

Reset ECU, check if engine temperature is consistent (thermostat) and only after you've tried those two start messing with the O2 sensor.

[aaronng]

aaronng won't a damaged sensor throw up an CEL? depending on damaged sensor, or wires, etc?

but it would make sense in this case, especially with aftermarket headers.

also, OP, stop typing with your nose, it makes it hard for everybody.
Yes, it depends on the type of damage. But, I've seen this happen many times with the CL9, both in Australia and also in the USA where the wiring is fine, but the inside of the O2 sensor was somehow damaged. The O2 sensor just thinks that the engine is running lean when it isn't and adds in more fuel. The sensor is still working and has not failed (technically), just that it gives an erroneous reading. That is why it doesn't throw a CEL.

[Mugen_Euro]

Guys like i said, the problem occurred before i had the headers installed so im thinking its not the 02 censor....
and GEG sorry bout my typing :)

[SuiJin]

CT headers - most cases changing headers will cause an error to the o2 sensor. more than likely o2 sensor or possible non acceptance of the headers.

[Mugen_Euro]

CT headers - most cases changing headers will cause an error to the o2 sensor. more than likely o2 sensor or possible non acceptance of the headers.

problem happened befor the headers were put in