A few weeks back, I had a 10mph bumper-to-bumper hit with someone. No real damage, except that the plastic fan (in front of the radiator) broke and had to be replaced. After the new fan was fitted, the engine is not nearly as responsive under 3k as before (i have a Jim C. chip). What could the cause be? I have no clue... thx.
p.s.(the oxygen sensor was replaced about 12k ago).