stalling dx hatch
 

alright guys gotta 00 civic dx hatch automatic i just recently had the rear muffler replaced wendsday and then i just had the o2 senor replaced today but right after my o2 sensor was replaced i left the shop and i literally got to the stop sign and the car stalled and so i started it back up and after that it stalled at every stop light and the car shook a bit the rpms are a bit better since the o2 sensor was changed but the mechanic told me it could be the distributor cap? so my question is what are the symptoms of a faulty cap from yall's experience. thank you in advance

if the car drove ok into the shop other than a noisy muffler, and something was worked on in the shop, how can the distributor cap be bad. I would think its the sensor causing some of the stalling.