Combed every site need some advice on this code.
2004 g35 coupe 70k (no mods)

P1283 - lean condition pre-cat
Replaced o2 sensor bank 2, sensor 1
Replaced spark plugs
Mechanic did a smoke test for intake leaks replaced air box.
Cleared self-learning

Code back on. Mechanic tells me I need injectors cleaned.

Asked him to scope he doesn't have a scope.

Car runs like a clock no hesitation, no idle issues.

Its like he is shooting in the dark.

Infiniti dealer tells me they will charge me $115 to diagnose. I have had issues in the past with a maxima where nissan dealer never was able to solve the check engine and I had to eventually get a dmv waiver for emissions.

So I'm leary about the dealer route.

Please any advice would be appreciated. 1283 seems to be a common code for g35 and 350zs but no one seems to have resolved on forums.

Thanks Madness

 

That's weird...the CEL in my 2005 G35 coupe just kicked on, within a few days after turning 70K miles!!!

Took it to a local auto parts store (they do free CEL code scans) and it showed "P1283".

The thing runs like a top, no rough idle, tons of power, no change in gas mileage.

Thinking about buying a code reader and resetting it.

 

Have you changed out your PCV valve?
$13 part from the dealer and can cause this issue - takes 5 min to swap as well

I would recommend swapping BOTH pre-cat O2 sensors if you are getting that code and it doesnt go away with the PCV valve.

Failing O2 sensors can go bad slowly so degredation isn't as noticeable. Pre-cat O2 sensors run the feedback for the ECU in closed-loop. Although its not super common to have them fail at 70K its possible at any mileage. CHeck the PCV first though.

 

Thank you very much for those suggestions.

I put a fresh K&N air filter in last night, and also added a bottle of fuel injector/system cleaner into the gas tank.

I have not replaced the PCV valve, but will do that tonight.

I am planning on buying OBDCOM (software and cable) for reading and resetting trouble codes. Then I can see if it is fixed or needs further repairs.

If the above doesn't work, I will move to the pre-cat O2 sensors.

Also, one question:
Would a bad catalytic converter cause that code? I'm asking because everything was good about a month ago. We went on vacation for 1 week and the car sat in the garage. When I started driving it, I noticed the exhaust "note" sounded different (slightly muffled compared to what I remembered before vacation, especially during a hard acceleration). So, I'm wondering if the converter or muffler has some blockage that may have activated the code??

Thanks again!

 

Its possible. There have been several people with catalytic converters who have had them come loose and move around - sometimes causing blockages.

 

2005 G35 sedan
Just bought the car and failed smog. No trouble code but blackish smoke from exhaust. What was the result of your problem?
What did you repair??
Thanks

 

Plug in an OBD2 scanner and make sure there aren't any codes, they don't always turn on the CEL. Also check your A/F ratio and O2 sensor data to see if the black smoke is a fueling issue.

Normally it either smells like burnt oil or it smells like gas, if gassy then it's a fueling problem, if oily then it's usually a worn out engine.