New here and wanting to rebuild the D16Y7 in my CX hatch. I have a CAI and full exhaust with header on it and since doing so it is running sort of rich. I have two questions:

First: Would a sensor have anything to do with it running rich? The check engine light is on and it threw back an emissions code (probably due to being straight through exhaust/cat).

Second: If that is not the reason (or still maybe even) when I rebuild the motor I would like to get it tuned properly to squeeze a little more power and efficiency out of it, now I understand this is not possible with the factory OBD-2 ECU, my question is what ECU should I track down to be able to do this properly?

 

This is most likely your problem if I understand what you're saying. Don't know what kind of power you think you're gaining with all those bolt-ons with that engine.

 

Pull the CEL code(s) and post it.

 

Didn't think that the ECU took the emissions sensor info for it's air/fuel ratio? Thought that the MAF sensor in the intake and the sensor in the top of the header (not sure what it's called) that would affect the operation of the motor

 

Checked it a while back when the parts were installed, I am a little far away from a scan tool, I don't remember what the code was but I remember it being about emissions, either saying sensor was bad, or that it needed a new cat.

 

Just jump the service connector -- see codes sticky.

Then reset the ECU, drive car, and see whether code(s) return.

 

Yes I know how to check the CEL codes, I am currently living a ways away from my shop so I won't be able to get the actual codes for a little while. Thanks though

 

You have a problem that is associated with a CEL code. Not sure how to help you without you posting the CEL code. It doesn't require a shop - jump the service connector. See the codes sticky.

 

I have done that a couple times now, it keeps coming up after about 20 minutes of driving.

 

It requires me being at my shop as I don't have a scan tool or any such item that I would be able to read such codes on.

I will post codes as soon as I am able to read them.

 

Wrong. See codes sticky. You need only a paper clip.

 

https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/how-pull-cel-d4-srs-abs-codes-code-lists-1901557/


This is water you're being led to..drink it.

 

Ohhh okay missed that. Will do that as soon as I can then, thank you

 

I don't see how you know the car is running rich...

Since the catalytic converter on a D16Y7 is on the Exhaust manifold, did you install an aftermarket?? And extend your rear oxygen sensor after installing headers and new downpipe???

Why rebuilding the Y7?

 

Smell upon start up and idle as well as fuel millage drop after instal (when everything states for better millage) (went from 40-45 MPG to 35-40 MPG)

And yes we lengthened the o2 sensor to the correct place in the aftermarket set up.

And rebuilding as it is burning oil and the clutch is starting to go and do not have the money to swap. Planning on a full turbo B or H swap eventually.

 

I can just imagine how you've been driving it since installing those bolt-ons....

Thats probably your mileage problem..


Its also hard to get a base MPG figure when your clutch is pooched and your engine is on its last legs..


A leaky header/manifold get get pretty "rich" smelling...

 

I have this same issue/same setup.

Car makes a "stinky" exhaust smell when started up/idled. Smells like a diesel engine with old glow plugs (ie. -- hard boiled egg-like).

I still have the full exhaust/emissions system/ECU/working CEL light. No faults. I suspect a leak somewhere downstream of the secondary O2 sensor.

 

Nothing leaks everything is tight. Clutch isn't bad just figure if I have it apart might as well do it. and as for the motor it hits 4k shifts and runs at 3k down the highway no problem, pulls hard all the way. And it's just starting to burn oil (probably from me pushing it a little hard)

As for the smell its not a diesel smell at all, it's a gas smell, as in when you are in the car and start it you can smell gas and if you are behind it while idling you get the same smell.

 

Check whether the alternator is overcharging the system.

 

^^^


Splain....

 

An alternator that overcharges the system can destroy the battery, among other bad things. One sign of overcharging is the production of a rotten egg (sulfur) smell by the battery. The next step is that the battery explodes.

 

Alternator overcharging is not my problem.

 

Gotcha!

 

Look up Non-fowlers. You don't have a cat anymore and that will solve your problem.... Put it on your rear O2 Sensor and it will get rid of the cel and your wont run so rich and it will still pass emissions too...

 

^^^


I thought the rear oxy sensor was just to insure the cat is working...

Only the primary oxy has an effect on fuel....