Okay on my drive to work today my Service Engine light decided to come on. I was going around 70 MPH and randomly looked down and it came on as I was looking. There wasn't any weird noises or loss of power so I'm thinking it's something minor (hopefully). Maybe an O2 sensor? The car is an '07 G35x has 72k miles on it so does anyone know of any issues that tend to occur around that time/mileage? I hope this isn't going to be anything pricey, I got a cruise I'm paying for lol and don't want my alcohol spending money in the Bahamas going towards my car haha.

 

Is this just a service interval indicator, or is it the MIL? (Malfunction Indicator Lamp)

Our cars have both. The Service interval indicator is just a user programmable timer you can set to remind you to do routine maintenance. The MIL is an ECU detected fault.

 

if its the yellow CEL then it could be many things go to local auto store and have them pull th code for free, also chk ur gas cap is tight, that the most common CEL issue.

 

It was the orange SERVICE ENGINE SOON light that was in the bottom center of the RPM display on the left side. I'll check the gas cap when I get out of work but I haven't had to get gas in over a week and a half so I doubt it's that... If not I'll stop by AutoZone tomorrow morning and have them pull and clear the code for me...

 

Found out it was my O2 sensor like I predicted. Anyone know how difficult those puppies are to change? I know there are two of them but the AutoZone guy couldn't tell me which one was bad... How much gas mileage will I lose if I keep it messed up for a while and not mess with it?

 

The o2 is a pretty major contributor to the air fuel mixture. Right now it might be good, but as the fuel mixture riches, the worse your fuel mileage is going to get. On top of that, it creates extra heat in the exhaust. You're creating unecessary wear on the catalyic converter, which you must have in ALL states. If you let it go too long, you're going to be paying more money for repairs, than if you just got it replaced in the first place. It's going to leave some nasty black carbon in your engine, this stuff is extremely nasty. I am not sure of the tolerance, but it must be getting bad if the ECU is complaining about it. Do you know when the last time it's been replaced? From what I understand, they need replaced every 40,000 miles, but this figure could be off. I am not sure where the o2 is on that, but if you think you can do it yourself, it would cost a total of around $40.

https://g35driver.com/forums/engine-...1273-code.html

Is your car under warranty still, you could have them do it free of charge?