Why am I running rich

Would a aftermarker intake and exhuast cause motor to run rich on a 94 civic LX? If that couldnt be a reason, what could.

How rich are you running? Weak igntion, bad sparkplugs, bad sparkplug wires, dirty fuel injectors, bad O2 sensor etc etc alot can cause the car to run rich. What else have you done to the car? When was the last time you did a tune up, including changing the distributor cap and rotor along with the plugs.

plugs and wires are okay, cap rotor, not sure, anything ealts not sure. Im running 2.25 inch straight pipe tubing with resonator from cat back, no muffler. The intake and exhuast are the only mods i have to motor. Can tell its running rich cause it blows black smoke everywhere. Only does it around 4000+ RPM

if its only doing it at 4000 rpms id say its your throttle position sensor

yes its more than likely your TPS sensor , but I would check the PCM for codes !!!!!!!

How do you know your running rich, do you have a wideband o2 hooked up?

Um lots of black smoke, could be running rich all the time but just not visable. How would i check the TPS if its shot

Other thing i forgot to mention, could it be a vacume leak. There is a hard peice of plastic on the end of the hose that goes in the intake, that sits half way in cuase it isnt long enogh to reach to the valve cover with the house all the way in.

Checked for codes today, nothing, im ganna fix the exhuast manifold leak tomarrow and then test O2 senser alot with map and TPS

sorry for posting again, but how about a crappy cat, it looks pritty beat.

Checked for codes none, fixed my small exhuast manfold leak, seemed to help cut that black smoke back.