TwiztedS2K

Well, you see, I didnt really put on a single, they cut my 2.5 about half way back, right before it branches into duels, then the welded the rest of my 'single' exhasut on. I didnt know if the fact it isnt a true brandname exhaust had anything to do with it. After reading these threads over and over everyday, Ive heard of other people, not wiht hondas, but with dirty gas in their car. They seem to have similar problems, could this be possible? I think that it was mentioned earlier, but Ive filled up at Cheveron ever since I got the car, with one exception, all of whcih have been 93 octane

TwiztedS2K

Another suggestion, cat? Isnt it true, that when your engine is cold, the 'pellets' in your cat are not yet warmed, allowing a nice easy flow of exhaust , however, after time , these pellets can melt and the less of them, the hotter the inside of the cat may get, causing the area that which the exhaust flows through to get smaller and smaller, which leads to bad backpressure when the engine and/or temp outside wamrs up? This was something that popped in my head when i realized that it is "ok" in the mornings, not completely good, but ok, and gets worse as the engine temps warm up.

xviper

If the cat elements melted, they'll stay melted. They won't magically "un-melt" when the cat cools down. Besides, if the cat goes bad, the O2 sensor will see this and a CEL would come up.

TwiztedS2K

Ahhh, I did'nt think about that, my bad

Dante(suzuka)

Update: I had a similar problem a couple pages/threads back. Dealer replaced the spark plugs. The problem happened again after that but when I took it in they could not reproduce it. I got the car back and have not had another problem since. It's only been a week and a half but I'm mostly confident it was just a little trash in my fuel system and worked itself out. Good luck to others and I'll see if this happens again.

NorthCyprus

Well, thanks you all for the posts again. I'd like to remind you that i dont, and never got a CEL. I checked the car in Honda where they connected it to their laptop but everything was fine. I think the o2 sensor might be causing this, i'm not sure about the cannister because like Xviper said i'd get a CEL for that. My problem is not the ECU or the MAP bcoz i changed them. I've been filling up with 100 EU octanes for a long time now, it's been more than 10 tanks. I'm so sure this has something to do with either the fuel, air or spark.
The other possibilities listes such as;
-Catalytic Convertor,
-O2 Sensors,
-Cannister,
I'de get a CEL for all of these wouldnt i?
The worst thing about this is that i dont get a CEL.
The Clutch?
I'm starting to think that the clutch might be the problem but then wouldnt it be same all the time? Weather and driving time affects this problem. Hot weather it does it more, cold it does it less. In hot weather it starts earlier , cold weather it starts later. Fuel consumption goes crazy! Plus:
My mechanic said maybe the problem goes away after some time. Sounds stupid to me but is that a possibility?
Believe me, bcoz of this i might sell my car but i love the damn thing! I never want to sell it! i hope i dont have to bcoz of this. I tried everything people like u read before in my posts.
I see a lot of people experienced this kind of a problem before but all solved with simple things such as sparks etc...
What is my problem?

NorthCyprus

PS Another friend of mine had a similar problem with his 2000 s2k. He switched to 100 octanes and his problem was gone after a while. He said 2-3 tanks. I 've been using quality petrol for more than 10 tanks!

lukep6470

Have you checked your alternator? When the car starts to play up it could be dirty power to the ECU.

Hook a voltmeter (preferably analog) up to the power and ground of the ECU and see if there is any change in voltage when the problem happens.

This is a JDM car so is 100 octane enough?

TrueDrezzer

You mentioned running 91-95 octane before running the 100 now. Perhaps when you ran the lower octane, sufficient detonation did some damage somewhere...

...but I think a CEL would be thrown for that.

Seems like you've replaced everything I can think of except for those O2 sensors. If they're on the fritz and not regulating the right lambda value, you'll definitely have driveability problems.

///Robin

TrueDrezzer

You guys can do a g00gle for octane ratings in detail, but briefly: you see on US pumps the formula they use to get the octane rating: (RON + MON) / 2. In the EU, it's just the RON value.

///Robin