p1126 and p0420

Question

Changed theromstat and coolant temp sensor.hoping p1126 caused p0420 code .Also Code p1126 is different for this year. I don't know why .Before I found that out I changed out my Throttle sensor what a s.o.b. that is and codes still there. You could imagine how pissed I was. But I'm not an expert and shouldn't rely on stoner working at auto zone to really know what he's talking about unless he got it twitted to him. Anyway hope someone sees this and catches it as the throttle sensor change is not easy even though its two f-ing tiny screws.

Answer 1

Size matters. P1126 for a Nissan 2001 GXE with a 2.4 engine size this would be for the engine coolant temperature not reaching specific temperatue or operating temperature, If this is a  GXE with a 3.5 which would make it a 2002 year model P1126 would refer to the Throttle control motor relay it the engine size that make the difference. As long as there is a DTC stored the catalytic is affected. The purpose of the CK ENG LT is to protect the catalytic convertor. When the CK ENG LT appears this basically means the vehicle is not operating at manufactuer specifications.