Brown smoke at WOT from 4500-redline. What could be causing this? Keep in
mind my car has 124,000 miles. Its not oil because I check it and its not going down. I think it could be mixture, maybe catylitic converter, or a sensor. Anyone else with the same problem?

Kris -- 1990 240SX
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I had a similar problem, and tracked it down to a bad connection in the AFM connector. I have a 1990 with 119K miles, so it could be a common problem.

Derek Waters

I have a 1990 240 with 305k on it.
I would blow O2 sensors every 3 months and the car burned so rich that it coated my back end in black stuff! The timing chain guides on the 89-90 SOHC engines were garbage and I found mine shattered in my oil pan.  Changing the chain, gears, and guides is a pain but my car doesn't blow smoke anymore. Give it a shot
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