new to me 92 Civic VX mpg ?'s/mods

[comptiger5000]

If that exhaust leak is before your O2 sensor, it's a problem. It'll throw off the O2 sensor reading, possibly enough to make it run so lean it has no power. Fix the leak, and see what happens to the power.

[turbothrush]

If your car has the original exhaust then the cat. will be bolted directly to the exhaust manifold and the oxygen sensor will be in the exhaust manifold. As far as mileage to expect my vx (with mpguino and lean burn monitor ) gets 56 mpg at a true 60 mph on a flat road with no wind. If I see more than that then I have a tailwind . Even a slight wind will make a difference.

[coletrain777]

tim3058 - I will try to download the helm manual tonight to get the procedure to test the o2 sensor. I know that it is something that I really need to do. Also, I guess it could be a tps problem... although normally in my experience with other cars they seem to give problems at idle as well (this car idles great). I don't get any codes or CEL's until I unplug the o2 sensor, and they immediately go away when I plug it back in.

comptiger5000 - The leak is after my o2 sensor (and my cat as well, I misspoke earlier when I stated it was before the cat). I just didn't know if a sizable leak would cause a back pressure problem that would in turn cause the o2 sensor to act funny.

turbothrush - My car does have the stock exhaust, and the o2 sensor is in the manifold. I don't know why I stated the leak was before the cat (brain fart I guess)

Thanks for all the replies guys, keep the ideas coming. I love an active forum!!!

Oh, by the way, I went out and cleaned the egr ports of the intake (even though they looked great). Drilling out the covers was really simple, and it was good to see that they were clean. I also took the time to clean the injectors and tips while I was at it. Now in the morning I will reinstall the intake and see it that made any difference (surely couldn't hurt).

[Old Mechanic]

Ignition timing could be an issue. Also look at the distributor to see if it has been moved from its original spot to adjust timing which could be an indicator that the cam timing is off by a tooth on the timing belt.

regards
Mech

[Ryland]

As far as I know NGK is the only maker of an o2 sensor for the civic VX, other companies sell it in their own box, but if it has the correct plug and is a 5 wire sensor then I would buy a discounted one, platum is also cheaper then a year or two ago so the price should be dropping.

[coletrain777]

Ok, I will check timing and update everyone when I do. I have a brand new problem that happened after I installed my intake manifold back onto the car, but I will start a new thread for that. Thanks for the advise guys, I will let you know on the timing once I get to the bottom of the other (new) problem.

[rolleur]

Just my two cents, but our VX behaved very similar to yours for a while. We tried a lot of fixes, but it turned out to be the 02 sensor. I think it was $389, but it got us back up from high 30s to high 40s to 50 or so with no other changes. The "dead pedal" feeling was really irritating. It felt like the car was either idling or floored - nothing in between.

Originally Posted by coletrain777

Ok, I will check timing and update everyone when I do. I have a brand new problem that happened after I installed my intake manifold back onto the car, but I will start a new thread for that. Thanks for the advise guys, I will let you know on the timing once I get to the bottom of the other (new) problem.

[coletrain777]

That's the feeling I am talking about. I am pretty sure it's the o2 sensor, I will probably bite the bullet and order one on monday. Keep the ideas/replies coming.