98 civic dx losing power

[Roger Ward]

I just got my 98 civic with the d16y5 engine in it. The car has headers and new pipes to a 4in tip. Its also a 5 speed. When i drive the car it dont take off that fast unless holdin the gas at about 2500+ rpms. The sometimes when going up hills i gotta drop to first and sometimes have 2 rev it still to get it to have the power to move. The check engine light is on and its 02 sensor bank 1 bank 2. The is only one 02 senor in the car there isn a spot after the cat just on the headers. New to the small engine cars so any help would b great.

 

[Joe Mason]

Welcome to small engine cars. There's no power on a 1.6 liter motor below 2500 rpms. But seriously, I am not sure what you're saying here. "The sometimes when going up hills i gotta drop to first and sometimes have 2 rev it still to get it to have the power to move."

 

[HeX]

Please try to explain yourself as clearly as possible so you receive more helpful responses. You may want to edit your original post for everyones sake.

It seems like your car had its engine swapped or at least the block, and it wasn't done properly. D16Y5 engines only pertain to Civic HXs that have two O2 sensors. Your HX ECU is not getting info back from the second O2 sensor and it may even be miswired to the first. This all depends on whether or not your wiring has been hacked up.

My guess is that they re-used the DX exhaust instead of upgrading to the HX. If you don't see the wiring available for a 2nd O2 sensor to go after the catalytic then you may be in for a project and will have to research wiring diagrams. If you do find the wires, then have a muffler shop weld in an O2 sensor bung (plug) after the cat and get the correct NTK O2 sensors for an HX.

Do keep in mind that even if the engine is all wired correctly with both O2 sensors, it may still need some maintenance for the sluggishness; EGR chamber cleaning, fuel filter replacement, new plugs, valve adjustment, etc. I had some similar sluggishness with my HX while driving up some steep hills and the maintenance and valve adjustment made a huge difference.

 

[Roger Ward]

Its not all the time i mean at times its just normal driving its like the car loses power. Maybe the piping is way to big for proper back pressure. but most often what happens is il be running about 25 in 3rd start up a hill and the car will start to die down rpms drop so il drop to second sometimes it will power back up and accelerate then other times it will still be dying out to where i have to drop to first and then it takes off although a couple times it will still act like its dying til i push in the clutch rev the car higher and release the clutch then it takes off like nothing ever happen. The car also has a rough idle that probably drops to 200rpms up to 1000 after coming to a stop. And been heavy smell of gas but no leaks anywhere i can see. As for the o2 there is to o2 plug-ins but only one sensor made in the exhaust system. The exhaust is all aftermarket looks like its 2.5 to 3in all the way back. Ive switched plugs to see if that will help but no luck. Is there a way to make it run just off the one plug or can i just bypass the senor all together and get it to run properly that way? The car has used 3/4 tank in 154 miles so its gotta be running super rich i would think.

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[Joe Mason]

That thing sounds like a mess. You shouldn't be smelling gas. Running super rich would give some explanation towards the motor running poorly. I think HeX hit it, a bad swap. Who knows what you've bought.

 

[Roger Ward]

Im considering a b18 swap. The only code thats running on it is just bank 1 bank 2 sensor. And i only smell gas after getting on it and coming to a stop and at start up. If i run 2000rpms the whole way or under 4000 i wont smell it usually that makes me think its running rich.

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[HeX]

You may be running extremely rich due to the ECU being unable to get a read off the 2nd O2 sensor so its sending too much fuel and yourecsmelling the excess coming out the exhaust. Verify your ECU is from an HX then go to a muffler shop & have them weld in the bung behind the catalytic (assuming you have one) and plug in the loose O2 sensor. Extend the wiring if you need to. That may be the lone cause of your issues.

At some point you should also inspect the injectors. HXs have the leanest CC injectors of 6th gen Civics so its also possible that the previous owner swapped in higher CC injectors that, coupled with the O2 issue, could be further causing the ECU to deliver too much fuel.

 

[HeX]

FYI, you may here someone suggest to get a non-fouler for the 2nd O2 but I believe it doesn't work on the the D16Y5s second 5-wired O2.

 

[Roger Ward]

I just didnt know if there was a plug and play that could cut the o2 reading from effecting the car. I plan on doin a b18 swap so does that engine require one or 2 o2s?

 

[HeX]

A D16Y5 ECU needs the 2nd O2. I'm not aware of a successful method to bypass the 2nd O2.

 

[Roger Ward]

Ok i wasnt sure. I didn know if a head swap would work and changing the ecu or getting a chip would work. Is it because its the economy vtec that it requires this second o2?

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[XpL0d3r]

Ok i wasnt sure. I didn know if a head swap would work and changing the ecu or getting a chip would work. Is it because its the economy vtec that it requires this second o2?

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Didn't read the rest of the replies so sorry if anything here is redundant...

Anything OBDII (1996 and newer) have two o2 sensors, one in front of the cat, and one behind it. Without the second o2, your ECU doesn't get a reading as it should. It also does not know that you have a working catalytic convertor, because the job of the second o2 sensor is to compare the reading with the first sensor. If the readings were to be the same, the cat isn't working, and you'd get a CEL for that.

Basically, your ECU doesn't know if you have a cat, all it knows is that you don't have an o2 sensor in there. This will mess with your A/F ratio and cause poor performance.

FWIW I had a "going bad" secondary o2 sensor.. it got a reading so it didn't trigger a CEL, but the reading was so different that it adjusted by A/F ratio to the point where once the engine was warm I had NO power on the low RPM band.

 

[Roger Ward]

So pretty much thats the only way to fix the problem is by adding the second o2.

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[lethal6]

So pretty much thats the only way to fix the problem is by adding the second o2.

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Yes. And a catalytic converter if you don't have one.

 

[Roger Ward]

When it comes to modding is this engine a good base or should i consider a swap?

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[HeX]

D-series engines have their limitations being that they're designed for fuel economy above all else, more so the D16Y5. So to answer your question, its a good modding base if your goals & expectations are simple & modest. If they're not then any d-series engine will be a poor option for higher end performance goals.

 

[Roger Ward]

What would you say the max hp to be safely pushed on it be?

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[HeX]

Theres a forum member who claims to get about 222hp on his turbo'd D16y5. Im not certain what else he's done to it. There's a recent thread about turbos where he was involved. Try to locate it. All-motor though, it'd be hard to get much higher than 160hp or so unless you spend a lot to custom build up the engine. Please keep in mind I'm not an expert on the subject. I'm only stating what I've read and heard from others.

 

[Roger Ward]

I get that. I was just tryin to decide if the skunk2 bolt ons i found were worth gettin or jus get me a b18 and swap it then build up from there

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[lethal6]

No bolt on is worth it on a d series unless that bolt on includes a full turbo kit. Especially not skunk 2.