I would like to see a plausable explanation of how the clutch can cause the engine to misfire and stumble.

I would also try the suggestions made, if I were trying to fix this problem. Regardless of whether the ECU was replaced or not, you still do not know whether you will in fact get a CEL when there is a problem. I thought that W1ngman and Xviper both had reasonable suggestions.

IF there just happened to be a problem with the car's wiring for instance, you can change the electrical components untill you are blue in the face and never fix this problem. HOWEVER if you don't check this out, how will it ever get resolved? It is very easy to cause a CEL condition. Another way to cause a CEL is to leave the gas cap loose.

This is offered in a very positive manner, I hope. I'm trying to help, not cause any trouble.

Good luck,
Bob

 

Another thought came to mind...has your mechanic measured the voltage at the battery? I can also see how this could be caused by corroded battery terminals and/or a bad system ground.

Just a thought,
Bob

 

U'r not being an ass i thank u for your time. Wouldnt all those cause a CEL, or at least be seen on the damn computer? I'll get them checked again anyway.

One question. WHat happens if i cancel my cat, where i'll have to remove the secondary o2 sensor aswell, and not use it anymore just pipe instead like i did in my Golf. What would happen? is it bad?

 

I'm thinking of doing that, before doing it i want to see what xviper thinks. I'm having thoughts that my problem might be a blocked cat.
If i put the cat out, can i put it back in later? does removing it have any disadvantages?

 

I read a problem which sounds like mine in a thread, said it was a bent valve or something? is that a possibility do you think? Is that really bad like it sounds? how to fix?

 

Hecash gives good advice. When he posts, you can believe him. Removing the cat and replacing it with a straight pipe (test pipe) is an easy thing to do and putting it back is also an easy thing to do. The only problem is the availability of a test pipe and the plug non-foulers to make the O2 simulator with.
A bent valve can also produce all kinds of weird conditions but I though you said your mechanic checked all the valves and said they were good? If you have a bent valve, you can determine this with a leak down test before you go tearing the valve train apart. Do you have some reason to believe you might have a bent valve? Usually, this is caused by a mechanical over-rev.

 

Now I'm not gonna put any words into Cyprus' mouth, but I see one of two things: 1) If the word in his quote above [brought] were a mis-spelling (said English is his 2nd language), then he has owned a 2001 for only 2 months. And I would take that to indicate he is not the original owner. Therefore, a mechanical over-rev would always be a possiblity for any 2nd owner of an S2000...sadly ...or, 2) Cyprus has slipped the ol' 6th-to-2nd oops . But seriously I doubt that myself. There is no room for his '01 to still be warranteed...so no reason to fib at this point. And all of this thread has been posts from him seeking an answer to a problem that has plagued him at least within these last 2 months of ownership.

Cyprus...you've actually *HAD* the S2000 computer hooked up to a diagnostic computer, and that computer has not identified a CEL when a known CEL condition has been created? If you have not done that...and are only "looking at the dash" for a CEL light, I would again caution that the CEL indicator in the dash could be faulty. This line of thinking is not meant to dissuade you from performing a leak-down test on the cylinders to rule out mechanical over-rev / bent valve. Just keeping that CEL thought alive in the face of the equally possible bent valve concern.

- Dave

 

hmm...he may have a bent valve from the previous owner, and the previous owner may have disabled the CEL light on the dash. possible eh?

 

Well i had the valve adjustments done, my mechanic didnt say there was something wrong with them, he said my engine was very clean.
I am my cars second owner, the first owner was in Japan, the car is a japanese edition. On wednesday i'm getting the
-Cannister , -02 sensor , -cat
changed. Hope it solves the problem.
I'll also get him to check for bent valve.

 

PS I checked the backup fuse, it's there. Mine is a japanese edition so i didnt understand what it said on the thing but i look at the photo Xviper sent and checked it, it's there.