hey i just dropped in a 2.4L twin cam for a 98 maibu. i think they pulled the motor form a 00 pontiac everything mounts up and looks good but when i run the car the exhaust pipe to the manifold turns red and it has the worst idle problem ive ever seen, when i disconnet the MAP sensor is calms down but it knock intermittenly.
Just a guess, but is the cat good, not clogged? The heat transfer from the catalytic converter can get so hot to turn the exhaust pipe red.
Also a leaky fuel injector dumping raw fuel into the cats will also turn it red. Hence the poor idle. Check the fuel pressure.
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