Vx can not maintain a speed in lean burn.

[tommytunes]

I have been looking for weeks now trying to see if someone has had this problem and solved it. recently when going into lean burn it drops in hard like a big stumble. And after that it stumbles and slowly drops speed until I am forced to come out of lean burn. It runs better in warmer weather. I have taken the intake off and drilled/cleaned the egr ports, nothing changed. From my reading on the form it is very rarely the actual egr valve. I have run a compression test with the results of 190, 175, 190, 185. I think this should be ok? Any help would be greatly appreciated!

[Rusty94cx]

What are the part numbers on your 02? Are you trying to climb a hill or just flat ground? More info.

[tommytunes]

It is all the time once in lean burn. Worse when climbing a hill but even on flat ground it is unable to maintain a speed. I will have to check the part number tomorrow and get back to you on the o2 sensor.

[Rusty94cx]

Also check the dumb stuff like tune up stuff. Plugs wires and air filter.

[tommytunes]

I should have mentioned plugs are new, fuel filter is new, wires are newer and tge air filter is good...

[Rusty94cx]

At freeway speed it is hard to maintain speed. I some hills require me to downshift to fourth to maintain lean burn.

[tommytunes]

where is the part number? i looked and can not find it. Also this is not only on climbing hills. this happens even when going down hill. The car ran great last summer and this winter until late. it seems to run better if the outside temp is above 60... idk if that helps diagnos the problem?

[tommytunes]

also sorry for the delayed response. selling my house so my time is thin

[Rusty94cx]

You could have a bad temp sensor or 02 failing. No check engine light. The 02 part number is etched right into the 02. Here is a link.
Lean burn Honda Civic sedan: 93 Civic d15z1 swap into LX 4 door (VLX) - Page 7 - Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com
Post 66 shows a couple of 02s. You should be able toaintain speed on flat Ground

[tommytunes]

Is there a way to test either of the sensors? I hope it is not the oxygen as I have heard it is pretty expensive for a new one...