I have a 95 Maxima and I put on a stillen K&N filter recently. When I start the car from cold, I am getting the following symptons:

1) A lot of black smoke from the exhaust
2) low idling RPM, around 4-500 rpm
3) A lot of jerking on the engine
4) Check engine light comes on with the error codes of 0102 (Check MAF) and 0304 (Knock Sensor, which makes sense because the jerking?)

One the car warms up, I reset the ECU and it runs like it has never happened before. I have not had a chance to follow the direction in my Haynes manual to check the voltage and resistance in the coil and the MAF connection.

Has anyone had this experience? What is a good price for the MAF?

Thanks!

 

0102
Diagnostic Trouble Code 0102 points to a problem with the Mass Air Flow Sensor. The MAFS is placed in the stream of intake air. It measures the intake flow rate by measuring a part of the entire intake flow. It consists of a thin film that is supplied with electric current from the Engine Control Module. The temperature of the hot film is controlled by the ECM a certain amount. The heat generated by the hot wire is reduced as the intake air flows around it. The more air, the greater the heat loss. Therefore, the ECM must supply more electric current to the hot film as air flow increases. This maintains the temperature of the hot film. The ECM detects the air flow by means of this current change.

This malfunction is detected when an out-of-range voltage is sent to the ECM. That voltage might be too high or too low.

a) An excessively high voltage from the MAFS is sent when the engine is not running.
b) An excessively high voltage from the MAFS is sent under light load driving conditions.

Possible causes include...
- Harness or connectors (the sensor circuit is open or shorted.)
- Faulty MAFS

c) An excessively low voltage from the MAFS is sent when the engine is not running.
d) An excessively low voltage from the MAFS is sent under heavy load driving conditions.

Possible causes include...
- Harness or connectors (the sensor circuit is open or shorted.)
- Intake air leaks
- Faulty MAFS

With DTC 0102 the ECM is supposed to switch into Fail Safe mode and limit engine speed to 2400 rpm.




Try to re-ground hte ground wire on the harness.

Try to clean hte MAF sensor element with rubbing alcahol.

 

I have cleaned it with electronic cleaner before. I am going to check the voltage this weekend. The part that really bugs me is the black exhaust when the car is started from cold. I'll check the grounding on the MAFS this weekend too.