when i start my evo it shoots out clouds of black smoke and the idle is unstable and i cant pass 2,ooo rpm on full throttle. the spark plugs is all black and smells like fuel. all spark plug ignites and works. change the maf sensor, didnt help. i believe a sensor is bad but i dont know which one? crank sensor,cam sensor,o2,? it seems to have a misfire and the timing is off? dont know what though? there is spark so im not sure of crank sensor. cam?maybe... what would a bad o2 do to my
car? anything would help. thanks

 

A bad front o2 sensor would make it run ruck but it would still run. I have driven over 750 miles on a bad front o2 sensor. SES light came on and wideband indicated a very rich condition. Car was slightly down on gas mileage but ran fine and wide open throttle was no problem because it was on the open loop map. Check the MAP sensor. I have one you can get cheap to test with if you like and if it is the problem you can buy one from the dealership and send mine back and I'll give you your money back. or you can just buy mine out right and if that's not the problem you have a spare!

Josh

 

if you want help your gonna have to post more info on your car, your mods if any, have you been tuned, you mention timing being off did you have cams installed?

 

Good point I forgot to ask if he has after market injectors and how they are scaled. Cam and cam timing obviously would cause some serious problems.

Josh

 

really stupid but did you check the obvious? Go double check that all your IC pipes are on. I know its stupid but that will give black smoke. idle will not be good, and cant go wot obviously

 

Wow now I really feel like an idiot! LOL That would make the most sense! LOL I still have to send you my map!

Josh

 

sound exactly like what happened when i had a loose IC pipe...