wont pass smog?the car is running too rich

[mr. brown]

93 240sx wont pass smog. the smog guy said it was running too rich, it failed the hc (ppm) test at 158, it has to be below 88. then the co (%) test failed at 1.51, it has to be below 0.50... i am confused because i rebuilt motor, changed the cat. got new egr and egr pipe. and new o2 sensor. got any ideas??

[r3v_v3ng3]

high hc are usually caused by your ignition system. have you done tune up yet? cap/rotor/wires/spark plug

[ANVIL]

also if your coolant temp sensor is bad it can cause it to run rich

[Cone Junky]

With that high of CO%, you're probably looking at a MAF problem. But like mentioned, the coolant temp sender can affect the mixture too.

[mr. brown]

i will give it a try. thanks a lot

[MastaYu]

check the o2 sensor