dooner24

Hello Civic community!

I purchased a used 2003 HOnda Civic Hybrid last year and it has problems when accelerating at low rpms when lightly pressing the gas.. mostly noticed in 1st/2nd gear when at a slow roll slowly accelerating. It's like it's not getting enough gas kind of feel. A little history:

shortly after purchasing the car the check engine light was coming on/off intermittently. I scanned the code at an auto parts store, they said the DOWNSTREAM O2 sensor. I replaced it. then the light was off for a bit and came back on, new code: UPSTREAM O2, replaced that, Engine light has been off ever since. But after both of the O2 sensors have been changed the MPG on the dash went from a consistent 49 MPG to 38 MPG like a flip of a switch - and along with the lower MPG came the hesitation/stuttering at low speeds. ???

I took it to a general mechanic figuring it was something I screwed up, he said he couldn't find a problem and to take it to a hybrid specialist.

I took it to a hybrid shop, the guy said it was a dirty air cleaner and he also said there were old codes in the Computer, so he cleared the ECU for $100... I wasn't convinced it would fix it but he said it was running great otherwise. I got the car (paid $140). Drove it to work today and exactly the same problem exists!!!! Frustrated.

Was resetting the computer codes really NECESSARY? Would you get the same result by disconnecting the battery overnight???? I'm leary to call the mechanic back because I almost feel like he ripped me off and didn't fix the problem.

Any thoughts or ideas what to do next? I can pick up a wrench and do work myself. Would the fuel filter be a possibility??? Any troubleshooting ideas are GREATLY appreciated. Currently only 61k miles on the car, the hybrid batteries are only 5 years old and everything on the dash looks good (besides bad MPG).

Thank you!!

ezone

49 sounds too high. 38 sounds realistic IMO.

Check the fuel economy numbers from the US EPA site
http://www.fueleconomy.gov/feg/Power...id&srchtyp=ymm




IF this is not a manual trans car, then it has a CVT trans and there are no first or second gears at all.

Start clutch shudder might be what you feel during initial takeoff.
Research it.
Change trans fluid a couple times and use the correct Honda CVT fluid, but don't expect much change in the feel of it unless you wish to replace the clutch pack--- and that's a partial trans teardown to do it.

Incorrect trans fluid can and will make the CVT trans do strange things.

Best to compare to a few other similar Hybrids to get a feel for how the CVT trans acts. Some people just hate it, some don't.

It is imperative that you replace O2 sensors with the exact same type and brand sensor that the factory put in there.

If it has dual downstream sensors, certain codes dictate replacement of both as a matched set.

You positive about the timing of that?

The only other thing I can think of right off that might make one of these buck/jerk/act funny is EGR. Disconnect the wire connector from the valve and drive it a few days, see if it makes any difference. The CEL will come on, just ignore it until you know if it makes a difference or not.

Problem: A dirty air filter will not affect gas mileage.
It may hinder performance, but not mileage.

https://www.fueleconomy.gov/feg/maintain.jsp

(It only took the EPA about 30 freekin years to figure this out LOL)

It's necessary because that's how he gets your money LOL

I'd like to see what codes were stored before they were erased, IF they were erased. I love documentation.
Disconnecting the battery does not erase all codes all the time, some must be erased with a scanner.
Parts store scanners cannot read all the codes in your car. There are systems they cannot touch.



Something wrong with visiting your Honda dealer about this problem?
Don't they have at least ONE individual capable of solving problems there?

There have been tons of software updates since the cars came out. I'd hope they got done whenever the battery was replaced, IF it was done at a Honda dealership.

Diagnose it first.

Nope.
Did you replace tires shortly before your fuel mileage dropped? Some choices there can really affect your mileage, believe it or not.


JMHO, YMMV