runs hella rich, need help

[RiversideS13]

ok my 91 ka24de is driving me nuts. it runs very rich and back fires when i shifting gears and left lot of black marks on my back bumper

I need you guys help me tell me what i had missed before i replace the whole engine harness.

I replaced spark plug, coolant tempterature sensor and the wire clip, a new O2 sensor. got better but still rich

checked the timing and it was ok

the only engine mod the car has is RSR exmag exhaust and a K&N drop in.

so is it possible for the MAF sensor gone bad? but no check engine light

thanks

[NI_YON_Zenki]

The fact that you have opened up the engines breathing passage will alter its performance,for the better ever think of that. .. .there should be nothing wrong with the installation of a KA harness, it's simple. .. . or try checking the resonator for any cracks, if so then it's like having a ported. .. .resonator, so you will run a bit rich from that. .. .

Just make sure you have no sputtering after around 4200 RPM in 2nd/ 3rd gear, if so, you're missing an alternator sensor connect. .. .(only thing I've encountered)

[RiversideS13]

thanks i just found out the ka harness is 950 dollars from dealer, but they suggested it might be a be a faulty MAF sensor.

[P4rD0nM3]

Did you check your injectors if they're leaking? Mine was hella leaking and I replaced it with used ones from RnDFactory and bam! From 5mpg I get 20-22mpg city.

[Nuisance Crew]

Just make sure you have no sputtering after around 4200 RPM in 2nd/ 3rd gear, if so, you're missing an alternator sensor connect. .. .(only thing I've encountered)

Hey, can you you explain this a bit, trying to diagnose a shutoff/sputtering around that rpm, thanks!