Hey guys. I recently bought an M37 with 73k miles. I’m posting here to get more help/opinions since it’s got the same engine as G37. Hope you guys understand.

After a week of driving it, ‘Service Engine Soon’ light came on and I had it checked at Autozone. It was P0240 code - ‘Catalyst System Bank 2’ and suggested solutions were Exhaust Manifold Gasket and Catalytic Converter.

I’ve also noticed the heater not blowing really hot air even when the temp is set at max 90 degree and one of the vents in the middle was blowing cool air when others were blowing warm, not hot air. I checked the coolant reservoir and noticed there was none I could see so filled it to max - but I didn’t noticed much different in heat.

Are the heating issue and the P0430 code somehow related? Or the code and the heating issue two separate issues? The car drives fine overall and I’m getting 28MPG in 80% Highway driving.

I like the car overall but am pretty disappointed at this point with the issues. Please give me some suggestions as to what to try first.

Hi the coolant may have had to run through the whole enigne. did yo fill while the car was on? or ran car for 5 min then check level? the other code I would try google and youtubezzzzz.