Sooty Spark plugs

[Bichicor]

Hello everyone, I'm a long-time reader of this great forum, today I need help. I have a 1994 Sport with 48,000 miles(great SUV), about a month ago the "CHECK ENGINE" light came on and it started to lose power on the highway, sometimes I also notice a bad smell. I checked the spark-plugs today and noticed some flat (non-shiny) soot and I also saw a dark smoke coming out of the pipe. I think the problem is due to incomplete combustion or too-rich mixture. I don't have access to a code reader, although I'm planning to buy one.Can anybody please help me with this? Should I buy new spark-plug wires? Could it be the Oxygen Sensor? What could it be?Any help will be greatly appreciated. Thanks

 

[performancenut]

You are right; poor combustion leads to rich conditions; bad spark plug wires, poor plug condition, and wire/plug connections could indeed be a cause of this. You have little to lose with a plug and wire replacement if it has not been done in a reasonable period of time.

 

[cfkane]

Although the mileage is low, at 10 years of age many of the components could be experiencing failure. If you have access to a scanner see what codes are coming up in the analysis. Absent any definitive symptoms go through it one step at a time, simple items first, save the expensive items for last on the list. Plugs and wires are a good starting point.