i just failed my smog test again. the car has 200k miles but in tip top shape. 1st time it failed n needed some work.. i was told high hc 300s. Had the cat replaced n adjusted the valves.. still failed again.. PLS HELP...

 

How hot was the engine when you went to get tested? Also have you gone in and cleared any trivial OBD codes? Also would help to know what year the car is.

 

the O2 sensor can be bad.

 

i drove the car about 10 miles before getting it tested again.. civic 93 Si.. no engine check light or anything..

 

the quality of the cat could effect it. Also i hear when you have a new cat put on you have to break it in some.