2000 G20 Service Engine Soon Light

[markwapg]

Took my 2000 G20 to my local independent mechanic. He diagnosed P0170 System to Lean Bank 1. Said the car needed a mass airflow sensor and PCM reprogrammed. He can do the sensor, but said the reprogram was proprietary to Infiniti. Suggested having all the work done at the Infiniti dealer. Dont want to go to the dealer... Car seems to run OK with the light on but wont pass Illinois emissions. Suggestions on service besides dropping $$ at the dealer. The car has 51,000 miles. I live the western suburbs of Chicago.Thanks

[nametakennow]

There's no PCM reprogramming required. Simply replacing the part and using an OBDII scanner to clear the code causing the SES light will do the trick, though the light should go away on its own after awhile with the part replaced.

However, I'm not sure a MAF sensor makes much sense in this case, as when it has problems the car doesn't run properly, as in lean to the point of hesitating and/or stalling. It sounds like an oxygen sensor issue to me. I'm not sure which sensor would need replacing.

Hmmm... I'm seeing P0170 as Fuel Trim Malfunction Bank 1. Given that your car runs fine, I again think this is related to your oxygen sensor.

Are you getting lower gas mileage than normal? I'm thinking that it's your primary oxygen sensor.

As far as solutions, the solution would be to get a new O2 and replace your bad one, but if I'm wrong and it's the secondary sensor, you're going to have replaced the primary for nothing.

Drop in on the dealer and find the technicians, ask one about the code and explain that the car runs fine. He/She will probably be nice enough to tell you what's wrong for free. Head to the parts department and order what you need, then install it if you can. An oxygen sensor would be well within the skills of even the most novice wrenchman. If you want, download the Factory Service Manual for your car here.

Welcome to NICO!