dgreen78

Just picked up a 98 Hx with CVT trans. I noticed it has a 4-wire sensor and from reading on here I learned the auto trans models have this and the manual trans have the 5-wire wideband sensors. So my question is does the auto have lean burn capabilites? How do the 2 different ECUs differ? If the HX does not do lean burn then what are the benifits over this setup as suppose to a DX/LX?

Texas4door

Which sensor, O2?

dgreen78

Yes, figured the "wideband" would give it away but I guess not.

Kista20

Cvt version is not wideband. The hx's are the same for the most part being the only differences auto/5 speed or 49 state federal or cali versions.

dgreen78

Yea, thats what I said in my initial post. The question is: does the auto ECU have the lean burn function?

Kista20

No it does not... they did not include that feature.

dgreen78

Is this your guess because it does not use a wideband or do you know for a fact? Whats your evidence?

dgreen78

I found this thread were a guy states the CVT does use lean burn....

http://www.gassavers.org/showthread.php?t=7282

"the usage of the CKF sensor is what is used for lean-burn on the CVT version of the HX. The benefit of this approach is it allows them to use the cheaper 4-wire O2 sensor instead of the 5 wire (7 wire) wide band O2 sensor. The reason they can do this is because there is no "lockup" with a CVT transmission and consequently the "acceleration" of the crankshaft is completely isolated from the transmission. Therefore the CVT transmission makes it possible to use this method of detecting how lean the fuel mixture is. However when you have the transmission and engine "locked up" like with a Manual transmission, using the crankshaft acceleration to determine how lean the fuel mixture is isn't possible due to the way the engine can be loaded by the transmission. Also keep in mind that while I'm sure this method of lean-burn works pretty well, it's no match for using a wideband O2 sensor and consequently the CVT HX doesn't have the precise control over the leaning of the fuel mixture like the M/T HX does"

Seems like their are a lot of opinions on this but know one knows 100%

Kista20

It's just that the cvt versions are so few and far in between they also wern't really all that popular. It wasn't that good of a transmission nor any other honda automatic for that matter but the cvt's were absolute junk and expensive to repair that typically the person either swaps it for a different one or converts it over to 5 speed.

I have 97 & 99 hx's but both are 5 speeds, one is 49 state and the other is cali spec. If I had known the one had cali emissions I prob. would've passed on it but I did get it for a good deal. In the beginning the fuel mileage wasn't all that great but it had some egr issues and I should have solved for the most part and the mileage is almost the same as the other one. I get 43 and 40mpg respectively without trying too hard. I don't really know what the cali hx was rated to get, the 99 holds one extra gallon of gas and with that extra gallon it goes the same distance as the 97 which at the cost right now is an extra $3.55 per week since I use one tank to drive to work for 5 days.

Texas4door

LOL no way
We just went over this at the shop I'm at
XD
Girl came in with a bad O2 on a HX CVT, and we called O'Reilley's for the part. Turns out the O2 sensor type matters if it's manual or CVT. The parts guy was like: wtf Honda
XD

Crazy stuff, man

dgreen78

Thanks, yea I am not sure about this CVT trans in my car. It seams to be slipping? I thought it was a clogged cat or the timing was off but I checked and replaced everything including cleaning EGR ports (which were all plugged). I found a used trans at the local pull-a-part for $100 but who knows if it works. Would hate to spend the time swapping it out and have it not work. Another option is a Jap spec CVT for $500 with a 1 year warranty. I am debating on doing a manual swap but it seems like a lot of work. Maybe worth it to sell it and just find a manual.

I have been debating on getting an aftermarket wideband (AEM) to see if this thing actually gets into the lean burn range as no one knows if it has the feature or not

grumblemarc

iTrader: (4)

I'm curious. Whether it does or does not, what does it matter? Right now the car is what it is.