Rep Power: 0

My problem. When I start out in first gear, the engine wants to bog down almost stalling but never does. Took it to the shop, diagnostic said upstream o2 sensor. I replaced it, they cleared the check engine light. Then driving down the road it happened again, what could be the problem

 
Rep Power: 234

We can't help if we don't have a code. Just taking a stab in the dark but, I bet you have a P0420 code. If that's so, you need a new cat converter.

 
Rep Power: 214

Did the check engine light come back on.

 
Rep Power: 0

i have a problem its been so long since i been here i forget how to start a new post... sorry!!!
after my car warms up, under light accleration (1/4 throttle), up or down hill, theres a snapping or ticking noise.... 4th gear 2200 rpm its the worst... it doesn't do it when the engine is cold... i was thinking it was a belt so i got a smaller belt to bypass the a/c unit and it made no difference... the a/c pulley wobbles a bit i figured that was normal since it didn't help with the smaller belt and how the clutch for the a/c was not engaged, the p/s pulley does not wobble, the alternator pulley does not wobble, and the crank pulley does not wobble. the only belt left is the dirtiest of them all but, anyone have any pulley problems on the timing belt????
under 1/4 throttle it makes the noise, by 1/2 throttle it goes away, it doesn't do it any other time except 1/4 throttle....
anyone ever have a problem like this????????

i adjusted the valves a month ago, and replaced the oil pan gasket... all ive been doing now is playing with the tension on the drive belt and using 1/2 throttle or no throttle everywhere i go..

the engine - d17a2 w/ a/c. 2002 civic

 
Rep Power: 0

yes the check engine light came on again.

 
Rep Power: 234

Do you have the specific code?