<DIV id=post_message_2739820>I am an auto mechanics rookie, who is trying to save some bucks. I own a 99 Integra GSR with 93,000 miles. I am troubleshooting a low speed sagging problem (LSSP); i.e., the engines runs rough at low rpms (&lt;2,000). The timeline of my troubleshooting adventure transpired as follows:

http://www.honda-acura.net/forums/im...lies/smile.gif Performed a tune up; i.e., changed spark plugs, wires, distributor, rotor, and fuel filter.
http://www.honda-acura.net/forums/im...lies/smile.gif Changed the timing belt with the assistance of a professional.
http://www.honda-acura.net/forums/im...111;nfused.gif LSSP surfaced shortly after the timing belt change. Car idled great and ran smoothly at higher rpms (&gt;2,000).
http://www.honda-acura.net/forums/im...es/biggrin.gif Changed to correct spark plugs after I realized that I put the wrong ones in when I originally tuned it up.
http://www.honda-acura.net/forums/im...lies/frown.gif After about one week, the LSSP resurfaced and the car began idling roughly, the fuel economy decreased, and the exhaust gas appeared heavier than normal.
http://www.honda-acura.net/forums/im...lies/smile.gif Changed the oxygen sensor (before catalytic converter). The spark plugs appeared black.
http://www.honda-acura.net/forums/im...milies/mad.gif The engines idles better and the exhaust appears normal. However, the LSSP problem reappears when the engine is up to operating temperature.
http://www.honda-acura.net/forums/im...111;nfused.gif What next? I will clean your toilet(s) if you can suggest the solution.

Regards,

Deniroisgreat</DIV>

well, I at one time had a b18c5 1997 and did a full rebuild. I ran into the same thing but turned out to be something very obvious. I was off on my timming. Believe me, it doesn't take much. On the low rpm range the car was very sluggish. when i got to vtec the thing ran like a raped ape. The timming adjustment for me was just with the distributer. Being as you replaced the dist. I would look there(use a timming light). I hope this helps. If i can think of anything else, I will get back with you. lemme know. Oh, everytime I make any change to my car, I reset the ecu. Take neg terminal off battery for about 15 min, then put terminal back on. With all acces. turned off turn the car on and don't touch it. let it idle until it warms up completely. turn it off and see if that helps. I have had that help in the past.