Hi! I have a US market 1995 200SX (SE-R) with about 148K mi. Over the course of the past year, milage has been slowly dropping (from 27 to 22 mpg). Now, when I brought it in for inspection, it failed emissions due to high HC (it literally pegged the machine). Eventually I was able to get it to pass (once) but it still seems to run rich. So far, I've ruled out the following causes due to replacement of parts: MAF, O2 sensor (the one in the exhaust manifold), coolant temp sensor, timing, plugs/cap/wires/rotor, ECU, and timing. So I am stuck with a (probably) intermittantly rich running engine that doesn't respond to any of my fixes. The only check engine light I have gotten is a flashing check engine light that I was told is the cat overheating trying to break down all the emissions. I was wondering if anyone had similar problems with a US market SR20DE. BTW, the engine and emissions equipment are completely stock. Thanks.