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.
Looking for a Used Malibu in your area?
CarGurus has 51,317 nationwide Malibu listings starting at $1,550.
Search Chevrolet Malibu Questions
Chevrolet Malibu Experts
Related Models For Sale
Used Cars For Sale