[Hot Brass]

Just got thinking and I have noticed lately(for me at least), the availability of intakes systems,'header' style exhaust systems,which no doubt allow the engine to 'breathe' better and allow better air and exhaust flow,but does the engine management system on the 9th Gen adjust the vital air and fuel mixtures automatically,or does the car have to be brought into Honda for a "manual" air/fuel mixture adjustment?. What or how does one resolve a 'check engine' light when it comes on after installing aftermarket exhaust or intake systems? Thanks,HB

 

[elelkoolj]

I have no check engine lights. These parts are tested before sold. If you get a light try resetting the ecu. A negative terminal battery pull will work.

 

[Miker]

Just got thinking and I have noticed lately(for me at least), the availability of intakes systems, exhaust systems,which no doubt allow the engine to 'breathe' better and allow betterr flow,but does the engine management system on the 9th Gen adjust the vital air and fuel mixtures automatically,or does the car have to be brought into Honda for a "manually" air/fuel mixture adjustment?. What or how does one resolve a 'check engine' light when it comes on after installing aftermarket exhaust or intake systems? Thanks,HB

No

So many here have put aftermarket systems and it sounds like they are "plug n play".

No personal experience though.

 

[1greek4u]

The only way you can get a check engine light is if you get pre-cat deletes and the O2 similators aren't working properly. It's also possible to damage the MAF sensor when you're installing an intake, but the chance of that is pretty low.

I'm of the opinion Honda ECU's adjust when something changes with the air/fuel mixture, and it takes a day or two for this to happen. The reason I say this is because sometimes after I install a new part the car doesn't feel any faster afterward (you would think you would notice an immediate difference more easily right after the install). Then a couple days later I'll be driving and realize that my car does, indeed, feel faster than it did before.

I'm sure there's going to be a bunch of people saying this is nonsense, which it very well may be. This is just an opinion based on some experiences I've had, not fact. Anyone else care to weigh in?

 

[Miker]

The only way you can get a check engine light is if you get pre-cat deletes and the O2 similators aren't working properly. It's also possible to damage the MAF sensor when you're installing an intake, but the chance of that is pretty low.

I'm of the opinion Honda ECU's adjust when something changes with the air/fuel mixture, and it takes a day or two for this to happen. The reason I say this is because sometimes after I install a new part the car doesn't feel any faster afterward (you would think you would notice an immediate difference more easily right after the install). Then a couple days later I'll be driving and realize that my car does, indeed, feel faster than it did before.

I'm sure there's going to be a bunch of people saying this is nonsense, which it very well may be. This is just an opinion based on some experiences I've had, not fact. Anyone else care to weigh in?

Not nonsense, it's just the ECU learning and adjusting to the new "parameters" the sensors are reading. After I do any of the following to my engine: new spark plugs, MAF cleaning, TB cleaning, I always reset the ECU. It learns much quicker.

 

[greg1c]

The O2 sensor(s) will send the information to the ECM to adjust the fuel injectors for any new intakes or exhausts. Unless you add a turbo or supercharger then you would need a new program for the fuel map and possibly higher capacity fuel injectors.

 

[Uncle Luc]

ECU is so smart it will learn/adjust new air/fuel curves on its own, older Hondas you would have to reset the ecu by disconnecting the battery or pulling the fuse for a few seconds

 

[Aviography]

Any car, which is just about all cars sold today, have emission control systems based on many sensor inputs, O2 sensor being one.

The ECU in the car will have some baseline parameters as initial values for amount of fuel at a given engine RPM based on some basic inputs such as manifold pressure, ambient temperature etc., but will continue to modify the fuel injector duty cycle to accommodate varying conditions based on parameters of other sensors, such as the O2 sensor.

Mild mods, such as basic header and intake, can probably be handled by the stock ECU and fuel injectors just fine, but any wild mods such as turbo/supercharger, 5" diameter straight exhaust, high lift / long duration camshafts, will overcome the ECU/fuel injector's ability to cope with the excess airflow, that's when custom tune and higher flow fuel injectors will be required.

 

[Hot Brass]

Thanks everyone! HB

 

[Schoat333]

All modern fuel injected engines can adjust A/F on the fly.

If you want to learn more about it research long/short term fuel trims, and also close vs open loop operation.

 

[obtrunco]

The only way you can get a check engine light is if you get pre-cat deletes and the O2 similators aren't working properly. It's also possible to damage the MAF sensor when you're installing an intake, but the chance of that is pretty low.

I'm of the opinion Honda ECU's adjust when something changes with the air/fuel mixture, and it takes a day or two for this to happen. The reason I say this is because sometimes after I install a new part the car doesn't feel any faster afterward (you would think you would notice an immediate difference more easily right after the install). Then a couple days later I'll be driving and realize that my car does, indeed, feel faster than it did before.

I'm sure there's going to be a bunch of people saying this is nonsense, which it very well may be. This is just an opinion based on some experiences I've had, not fact. Anyone else care to weigh in?

Nope. I don't think it's nonsense. Ive noticed the same thing. I have Stage 2 generic tune from KTuner, I had removed the 2nd cat and enlarged the exhaust diameter but afterwards it felt weaker. Days later it was running strong, I found this counter-intuitive. Recently, I instaled the RV6 down-pipe (all cats deleted) and it feels slow again... ughh...:bawling: I have a race on Friday so I hope it has adjusted by then.