Swapped from open pod filter to stock airbox setup now car runs funny

[crobaa]

Hi guys

My motor is a b18c7, when I bought the car it had an open pod filter attached to the stock intake arm. Today I changed it back to oem airbox with a pod inside and now it seems to have a stronger fuel smell when running and dropped idle rpm. Although the car seems to perform better now. I'm wondering if I need to reset the stock ecu or does it take some time to detect a change in airflow? The a/f ratio should be standard now seeing as it's stock setup so I don't see why the petrol smell would increase

[DakDak]

Yea man reset the ecu and I reckon you should be fine. Is this when you hit vtec? Cause I think your supposed to run more rich. Where is the smell coming from?

[crobaa]

I notice the smell more just sitting at the lights. Do you know how to reset type r ecu?

[jdm18c]

pull the ecu fuse in the engine bay and dissconnect the battery and put back after 5 mins

[tiksie]

Pulling the ECU fuse off should be enough but you can also pull the negative off aswell.

Try checking if the cars throwing any CEL's aswell.

[mocchi]

fuel smell?
does the car use charcoal canister?

[crobaa]

I don't think it runs a charcoal canister, it's not in the normal eg location anyway (near master cylinder on firewall right?). But the fuel smell was alot less prior to airbox install. I have 100cel hi flow cat and 2.5" system which is why I expect it to be smelly regardless but thought it would have improved with the airbox. Fuse is out now, just waiting till I can plug it back in

[mocchi]

most likely because when it was open filter, it sucks in fuel smell from fuel filter area.
now that it's closed box, it doesnt suck fuel vapor anymore.

charcoal canister should reduce fuel smell significantly.
doesnt matter where the canister is as long as one hose goes under car, and the other goes near fuel filter.

[trism]

Nah I don't think that sucking in the fuel smell has anything to do with it.

With an open filter it would have been drawing in a lot of air, and as such, the mixture would have been richer to compensate for this.

Now that you've enclosed it, it's not getting as much air, but its still putting the same amount of fuel in, and when you're sitting at the lights idling you can smell it bbecause its sitting in the exhaust, and you're not moving away from it.

Make sense?

So disconnect the negative battery terminal for 30mins, then start the car and let it idle for about 15 mins before going for a drive.

This will let the ECU relearn how much fuel it needs to dump.

[DakDak]

^ +1 Agree

[crobaa]

Ok, going for a drive soon and will report back. I notice there's no afm on my motor or at least it's not in the normal spot, isnt there some type of air sensor that is constantly telling the ecu how much air is going in?

[mocchi]

i think it use combination of map, tps and o2 sensor.
no air flow meter per se.

[crobaa]

So it will never check for changes in air flow and make the necessary fuel changes to the motor unless reset? Cars with an afm change automatically once they detect it right?

[mocchi]

i think it checks from manifold air pressure, checks from amount of oxygen left in combustion exhaust through o2 sensor and ecu calculates whether add/cut fuel trim. it does make changes, long term changes.

i think thats why theyre telling you to reset the ecu so this long term fuel trim setup is also reset. this is not the same as tuning. hope you dont mistake this as tuning your car fresh, or that kind of thinking.

[crobaa]

It should just make the ecu as it was when it came out from Honda right? And my engine is the same as it came out from Honda now so hopefully all is good

[trism]

The ECU has a set of parameters that it uses to determine things like how much fuel is needed, and relies on information from all the various sensors to make adjustments.

These parameters aren't fixed, they are variable, to allow the ECU to adjuust for things like air temp, amount of air, quality of fuel etc.

So over time the ECU makes slight changes to the mapping.

By resetting the ECU it reverses all these changes and puts the map back to its neutral settings.

[crobaa]

So if I never reset it, it would have gradually worked it's way back to settings for the air box? I just got back now and it felt much nicer to drive & no smell. Revs and idles smoothly too. Thanks for that

[mocchi]

good to hear that ecu reset works. good stuff bill.
itr airbox was it?

[crobaa]

Yep itr stock airbox. Seems faster, smoother, smells nicer, and surprisingly sounds nicer than open pod. I had a spare itr tb intake arm I'm using for a cai to the box too lol.

[mocchi]

add velocity stack too. but on topic, glad your issue worked out.