Hi guys !! It's my first post on this forum. I would like to share you my problem ...hope you will help me !

I searched on the forum for hesitation problem but my problem is a little different than what I found. I explain !

My car: Honda Civic SiR 99 (Si : US) with 39000 miles.
Modifications: just a muffler and a AEM short ram !

So, my car hesitate often and I haven't found the problem for about a year.
But, specifically, it hesitates when the outside temperature is hot. In the summer, it's hell !! Always hesitate everyday !! And when the problem surge, the engine make a strange noise like booooaaaaaa (a deep sound) when I put the gaz pedal to the floor. I know that it's not the Short ram ! It hesitates in all RPM range and in every gear. NO CEL CODE for the problem.

For now, it's almost winter, so the temperature outside is cold and my car have NO problem at all. So, I have something that is fragile to temperature changes but what ??? That is the question !!

Here is the list of things I done to try to solve the problem:
1. Change the fuel filter (my car run ok for 1 week but the problem come back)
2. Change the cap distributor + rotor (no change)
3. Change the spark plug (no change)

I have not change the spark plug wire because a mecanic said that they are correct !!

Note that the problem was here before I put the muffler and the short ram, so it's not that. I always do oil change regularly and put 91 octane gaz like it should. My air intake is clean .. not dirty !!!

So I wait for your help !! I really need it !!
thanks a lot

 

ok...take off your distributor cap and inspect all the wires connected to the ignitor. the ignitor is a square electrical thingy mounted on the bottom of your distributor with I think 5 wires attached. clean the connections if needed. good luck bro

 

Get someone to inspect your fuel system, including the pump, injectors, and lines. This could possibly have something to do with it.

And by the way, welcome to Honda-Tech.

 

Sounds like you may have a bad oxygen sensor. Disconnect the oxygen sensor closest to the exhaust manifold and drive the car. Your "check engine" light will come on, but you can clear that later. See if the symptom is gone....3gdude

 

If it was the O2 Sensor, I should have a CEL Code for that ??? Or not necessary !!

 

Your O2 sensor could be getting ready to die.
Unplug the O2 then see if it fixed it or just pick a new one up.

 

So most of you tell that is the O2 sensor. Other suggestions ??
Or it can really be the O2 sensor in trouble (without a Cel code of course) ??

 

I would look into the spark route.. just cuase something looks right does'nt mean it is right.. i would get a friend and use their spark plug wires to see if it helps.