I bought my altezza around 3 months ago. it’s a 99 rs200 z edition sxe10.
been trying to solve this issue. it’s a M/T. whenever I give full throttle, it boggs out and backfires all the way till I let off the gas. this happens at 4.5-5krpms and will not go past that rpm. however if I go easy on throttle, it will reach redline. I have replaced the fuel pump, fuel injectors, iridium ik20 plugs, valve cover gasket, and put in a new battery. cleaned the thottle body and the MAF sensor. I also had the car scanned multiple times to check for any codes, but every time it passes and says no faults. the idle does fluctuate a bit I can feel it needs adjusting but am not sure if that has something to do with the backfiring issue. any suggestions ? hope I was clear on what I mentioned.