i have a 99 gsr which has a check engine code of 45. MY car puts out a lot of black smoke and idles very low at times. i changed my o2 sensor; the idle air control. After changing those it ran ok for a while and started doing the same thing. Is there anything i need to change like the intake manifold?

 

you should check the fuel pressure and also the tune up parts. what mods do you have? any check engine lights?

 

i don't have any mods the only check engine i get is a code 45 which is either the system running too rich or too lean.

 

black smoke = rich motor. u probably have a bad O2 sensor

 

whats the remedy to running rich? tip of my exhaust is black

 

Ok,

Low idle, black smoke.. your running rich.

1st step.. check your FUEL PRESSURE.
Take it to a local shop, have them run a fuel pressure test on the car.
If it's high, probably your FPR or the fuel return pipe.
If the pressure is low, could be the fuel pump, feed pipe..could even be a fuel filter..

When's the last time your fuel filter was changed?

If absolutely none of that has done anything to fix the problem...

you'd have to resort elsewhere.. Maybe the MAP sensor or Purge valve.

you'll need a vacuum pump to test the purge valve.. it SHOULD hold vacuum.if not, replace it..

if none of this has worked at all..
replace the injectors..

 

still have the fuel pressure checked.
but i would replace the fuel filter since it is the cheapest and easiest if it hasnt been done in a while.

not changing out your fuel filter every so many miles contaminates the fuel supply system and causes problems like this where it could be a number of related problems.

treat your car right!

 

MAP sensor... very true. check it out. We had a 3-bar map sensor on one of our turbo cars. the sensor had a cut in one of the wires. This resulted in the computer dumping a whole shitload of fuel into the motor. we rewired it and the car ran great.