rosodigital

I picked up an 06 AP2 recently and noticed almost immediately that the exhaust, though stock, makes a clearly audible "poof poof poof" sound on initial deceleration, and also just sitting at a standstill giving like taps to the throttle. There is not check engine light and the car runs excellent otherwise. Its got 94k on it.

I kinda like the sound but just curious if anyone else with 06-09 AP2 has the same things... I have owned 2 AP1's and they didn't do it, I also spoke to and 04-05 AP2 owner that said mine sounded nothing like his.

The OEM Cat is in place, the Resonator is also in place. The car was lightly modded when purchased with wheels and suspension but it was otherwise stock...

Ideas are welcome. I will try to get audio or video but for now it would be nice to know if its something common or if I should be looking for some unseen engine mod done by the previous owner.

starchland

Check gaskets/leaks

s2000maniac

Valve adjustment

zeroptzero

That is normally associated with unburned fuel and misfires. Since you are not getting misfire codes I'd lean towards unburned fuel, at that mileage it's a good time to check the sparkplugs, which would be my first step.

Gotpepsi

"That is normally associated with unburned fuel and misfires. Since you are not getting misfire codes I'd lean towards unburned fuel, at that mileage it's a good time to check the sparkplugs, which would be my first step. "

If the exhaust is popping, you could be getting a misfire. But, the CEL might not come on until the problem gets worst. I drove with a popping exhaust with both an STI and my current s2000. Both took about 3 weeks for the CEL light to come on. The STI was purged with dirty injectors. And the s2000 is at the dealership getting a diagnostic on misfire codes, to check out an ugly noise, and to adjust the valves. On Monday I will let you know what they came up with.

rosodigital

the car runs and drives fine... weird...
i know what misfire/bad or out of adjustment valves sounds like...

Gotpepsi

Cant you feel that the car is running a little rough? For instance, the car shakes at idle, or when you lift up the hood you can see the engine shaking a bit?

rosodigital

nope its smooth... power delivery is good. There is nothing in the way the car runs that would lead me to believe anything is mechanically wrong. I don't know. Il'l poke around some more. Start with the cheap and work my way up. It sounds good tho. I'd hate for there to be something wrong, get it fixed and then the sound goes away....

Gotpepsi

True, I heard that a popping exhaust could also be due to the atmospheric temperature of the earth. The hot air from the car quickly hitting the cold abundant temperature of the earth could result in a popping noise (I don't have any hard evidence on this statement). Although there probably isn't anything wrong with the car as you said, certainly if there is, a check engine light would follow soon after. I can feel a rough idle, followed by a noticeable pop in the exhaust, plus a CEL that recently went off; I'm sure there is something wrong with my car. Sense you are sure about yours, there is probably no need to worry.

If you feel the need to poke around, maybe I can suggest a simple spark plug inspection. Highly corroded sparkplugs can lead to a car running rough. For optimum performance, Honda told me to go with stock NGK plugs.(part no. 7772) PFR7G-11S Laser Platinum Spark Plug. Torque specs is 21lbs I believe? I would poke around there, and probably run a fuel system cleaner through the car.

NNY S2k

Has the UK mod been done to the exhaust?
Levi